I had to rethink, what to make of this discussion. And some others, that seem to get stuck this way – with little titty-tatty-non-discussion sprawling in the wake.
Rethinking an earlier ‘reply’, I finally decided to stop getting into the rabbit hole of ‘who-is-correct-in-this-or-that-games’ (flavored by your / any brand of perception of what digital / document culture really is / means) as this is wasting anyones time and social energies (and karma ;-)), it seems.
Rethinking my first answer, and trying to get to the grounds of what causes unfruitful ‘two-sideism’ here, the one thing I realized (and that actually bothered me for a long time in the back of my head, as in my onw practical relation to DT) is this: there seems to be a tricky, and at times unhelpful ambivalence of what DT really is – and: should be – about (and in some extension: what different developments of digital, speak: document culture, and all it entails really mean (or, again: should mean) for a ‘document manager’ for ‘information hoarders and traders’, which basically stems from the 1990s).
With this in mind, I dawned on me that this (and some other discussions) won’t go anywhere productive – until there is some more (collectively shared) clarity on the basics.
– In this case this is: whether DT is (should be) used for some more serious / daily note-taking and writing – or not?!
Anatomy of an unfruitful discussion
Often in these discussions, some voices –regularly – fall back on the line that it ‘really’ is a ‘document organizer’. (Which, btw, I would think invalidates a third or up to a half of the threads in the DT forum, really). This – somewhat selectively used – ‘fall-back line’ mostly in terms of defending status quo, or minimal efforts to cater for some additional use cases – use cases brought up by either creative user understanding, or just by the developments of time and evolution of media use patterns.
Here is the thing: the notion of ‘document organization’ / ‘document management’ doesn’t say anything, really, if it is not better and more clearly defined at it´s base – and in concurrent (read: changing) contexts. And it does not really cover the functional and in-use reality of DT (or at least a larger part of its user base – … as discussions in the forums clearly show. It doesn´t even cover how DT represents itself to users.
For one: Clearly DT offers so many additional functions – like annotating, feeds, language analysis, providing dedicated ways to edit (some) documents etc. – A lot of this bends it towards a PKM tool, but a very particular kind (having this document organization / management capabilities ‘under it´s hood’). So *what is DT, or it´s (one??) purpose’? I think that this is kind of re-negotiated in all these discussion always anew, and kind of ad-hoc, with different people bringing in their very personal preferences – very often that is also simply saying ‘status quo!’ (even if that doesn’t really rely on a clear-cut definition of what DT is).
For two: It obviously seems to be used, and discussed in the forums, the blog, etc., and even presents itself as a ‘creative’ work environment, also particularly geared for ‘writing’.
On the webpage, you read something like:
“Collect, analyze, summarize, write: View all your data in one place, use tags to quickly organize documents, and write in editors optimized for plain text, rich text, and Markdown.”
… doesn’t read like a ‘document organization tool’, right?
Things do not get clearer by looking at official blog posts called and featuring ’ Creating Documents in DEVONthink’… 
Blurry reality, and shifting base-lines
Moreover, there appears to be some kind of ‘stereo-reality’ on the status quo and how it is perceived / represented. Again, in this thread some people can say, “I do not use DT for note-taking, just as a document management system. As, I have the impressions, do others.”; …while the people running DT can simultaneously state in the DT-forums, I do 99% of my note-taking in DT”. I could also start linking all the X dozen threads that at length discuss note-taking, gearing up DT for writing (of what-ever sorts, even long-form [there are even scripted plugins for that!], implementing the Zettelkasten method etc etc etc. – All things pointing to the fact that DT is factually discussed, used and to some extent presented as a (hybrid) writing tool – even if that is not its ‘main’ function (while I still would wonder: what is this ‘main function’, really?).
So, here we are.
Then, on this bases, people (we) are starting debating – what all that means for mister x, or mister y (women seem not to be too present… ).
But, I think these discussions will not – productively – be resolvable, until there is some clarification on this from the source (DT team); or, alternatively, an actively moderated approach to reach some baseline community consensus to start from, instead of a rather opinionated one. Otherwise discussions here will – given the fundamental ambivalence – by some necessity devolve in these kinds of chit-chats… forever. Just as they did / do here.
So, my approach after some point (and some of these ‘tit-for-tat discussions’) was: relax, retract, disinvest – and, faced with new challenges, or ideas: best expect nothing. ‘Then, you won’t be disappointed’. And you don’t have to unnecessarily burn (and waste) energy etc…
– Of course, that is not an approach one really likes to, or should be forced to take with one of your core – workhorse – tools, taking a center stage in many of your workflows.
But the trouble remains: DT is factually used for writing a lot (see forums), it is somehow vaguely perceived to lend itself to this (see also forums), and it is even presented to some extent in such ways (see examples above; more to be found via website etc)… but, then, nobody wants to put any kind of real ‘price tag’ on that question / dimension.
So, consequently, discussion can – and without moderation on any more conceptual level: does – go ‘anywhere’… ad infinitum. While ‘both sides’ feel like they can claim to be on base ground. Actually, to some extent I feel, ‘sides’ are in some way created by this ambivalency. Which is a little tragedy for any community / forum, of course…
Meanwhile,
some people still use DT as their 99% note-taking environment, or (try to) write dissertations, or cultivate their Zettelkasten, accommodating to ‘what is there’ – … as there are many ends to DT, and even more ways to ‘play it’. But, as in the case of writing, nobody really discusses what all this means for DT and its character (and: character development) on the conceptual / categorical level. Like, whether this has / should have implications on its UI etc. Nor, could this really meaningfully be discussed as long asDT simultaneously is… a ‘document organizer’… and obviously is not (in reality of functions, use, perception, presentation)…
my personal interest / stake here: having a decent MD editor – with ‘decent’ meaning: one transcending the coding and coders aesthetics / paradigm
My “personal” main concern was a derivative of this ambivalency (and a subset of the OPs proposition): as this ambivalency leads to a situation where it can simultaneously be stated that ‘MD has risen to be a “ubiquitous” text format’ (and, as I would add, especially in note-taking these days), and that MD is not of any particular interest, besides any other format that can be saved in DT.
beyond the inherent contradiction (ambivalence) of this, it is simply practically a pain to (try to) write with MD in DT consistently / regularly (… that is: for anyone who is not an ASCII-fan, or hobbyist coder), while one is simultaneously being told that DT “is set up to write in editors optimized for plain text, rich text, and Markdown”…
My wish
I´d still hope that one day I can make DT my real ‘go-to’ tool, allowing me to smoothly edit some simple texts without frictional pain, … no ‘full bloat editor’, just a way not to switch between a ‘rendered view’ (highly customizable via css’!) – and a stone-age code editor, not resembling this in any meaningful way, and really hard-to-get-to…
– but, who knows whether I am really entitled to such expectations and wishes… or to even raise this and talk about it… ?? And, as I would claim now, the answer to this lies in a deeper clarification about what DT is, and what it really wants to be… and whether it a tool that is also intended for some regular note-taking (‘writing’), or not.