In a game powered by imagination "window dressing" is the meat and potatoes of play. If mechanics are in the forefront then the game has already failed.
I simultaneously agree and disagree with you completely. I take the mechanics of D&D to be akin to the laws of physics in the game world. They are what give the story a common thread for resolving actions. Without the mechanics, D&D would be group story-telling (not necessarily bad) with the possibility for players to do whatever they want, at the expense of the story (I'd say that's almost always bad).
Therefore, I want a firm foundation of mechanics underpinning my game, primarily for action resolution, but mechanics that bring fun, balance, ease-of-use,
et al are also alright by me if someone's going to the trouble of codifying mechanics. I don't require the mechanics to perfectly simulate real life, just that they give some coherent structure to the game without being unfun in
normal play.
I couldn't care less about corner cases, hypotheticals or thought experiments that take rules to the breaking point. Referring to my mechanics as game "physics" example, these are like quantum mechanics. Sure, they're a thing, but have little bearing on my daily life. And just as I don't feel the need to constantly observe my cat, lest she be both alive and dead, I don't feel the need to worry about Asmodeus dying to lvl 1 Fighters.
Then, I get to go nuts with the "window dressing!" I can (and do) use my imagination to reconcile the mechanics with the game world as I envision it. This is why I never had a problem with abstract HP, DoaM or the abstractions found throughout attacks, saves, "hits" or "misses". I can very easily reconcile those mechanical concepts with my imagined exploits of fantastic heroes.
Granted, no matter how many times I might try to explain the way I actually imagine the mechanics into action, some will say that I'm pathetically grasping at straws, trying to hopelessly justify something that doesn't make sense (to them, and therefore to everyone). Thankfully, by accepting a window for what it is, I can apply all the dressing I want, with no need "to show or prove to be right or reasonable" my choice of drapery.