I don't..."unfair" to whom or what? You seem to think I don't think there are dissociated mechanics in 5e. There are. You seem to think I'm arguing something, anything, about 4e. I'm not. I understand this issue figured in the edition wars to some extent, but I skipped that whole thing. I probably can't sufficiently express how little I care about any of it.
The "dissociated" mechanics concept was specifically invented in order to criticize 4e for being bad at doing what D&D does. You may not have had a horse in that race, but that is (openly and explicitly) why the Alexandrian came up with the concept. By using it, you carry forward its history. If you have read his essays on the topic enough to articulate that others all too often get the concept wrong, then you already know that he specifically and explicitly used it to separate 4e from prior editions and did not do so with 5e. You have very clearly claimed to have read those essays, if you are claiming to know the correct meaning of the term better than others who use it.
Using one of the main weapons of the 4e edition war,
explicitly constructed for the purpose of that war, carries that purpose forward. Especially if you don't actually specify that you know its history but reject those aspects of it, and doubly so if you repeatedly specify that others often use the term wrong by saying you know what the Alexandrian said and meant.
As for the unfairness, that is specifically to martial characters. I already said this. Magic gets a BS blanket exception because it isn't even remotely real, so it can work however it works and not be "dissociated" even in principle, while non-magical things are beset by such problems (and, of course, always made weaker and less capable if one removes the "dissociation.") The entire "dissociated" mechanics argument is
inherently biased against non-magical characters.
I do care, somewhat, about dissociated mechanics. My preference is to avoid them. It's just that -- a preference -- and can range from mild (e.g. battle master superiority dice) to extreme (e.g. spend a poker chip to establish the NPC we just met is my long-lost mentor).
None of it has anything to do with abstraction.
I mean, it still does. Abstraction is one of the elements of "dissociation," by necessity: as defined in the source, it's mechanics that are abstracted away from the (fictional) situation at the level of character knowledge, choice, or action. As I have argued, "dissociation/association" is an incoherent term that picks and chooses only certain aspects of abstraction, diegesis, and "realism"/verisimilitude/etc., in order to say "X mechanic bothers me" but with a veneer of objectivity.
Again, if you (or anyone) admits that (1) these mechanics exist in essentially every version of D&D, (2) "dissociation" arguments unfairly target non-magical characters over magical ones, and (3) any use of "dissociation" as an evaluative metric is analogous to "I don't like steak because
I don't like the taste of red meat" and not at all analogous to "I don't like this steak because
it was improperly cooked," then there is no problem. But there is also basically nothing to discuss, because those admissions mean granting that (1) "dissociated" mechanics are quite acceptable in many contexts (thus invalidating its use as a disqualification), (3) only a personal prerogative (thus making no effort at objectivity, weakening or eliminating its use as an analysis tool), and (2) inherently geared toward a specific and controversial gameplay issue, caster supremacy (thus abandoning any pretense of neutrality in its use, as it has a clear design bias baked in). In evading the three layers I mentioned earlier, you have effectively neutered your ability to meaningfully discuss the topic beyond an expression of personal taste, and such expressions do not get us very far.