I think 4e DOES EXACTLY provide the tools to marry those elements. That is in fact what it does in spades. Things have standard definitions and when no other consideration overrides everyone knows what is meant and what the rule is. A wall that is blocking terrain does X. If it doesn't do X then IT ISN'T BLOCKING TERRAIN.
Lol... This has nothing to do with what I'm talking about.
Secondly, I do not need a rule to tell me "If there is blocking terrain, you cannot move through it. This wall is blocking terrain." That's common sense kind of things that shouldn't be coded in the first place. If you need the game to tell you that you can't walk
through a wall, then, man, something is wrong.
Now, maybe the game doesn't provide a definition that is suitable to whatever the DM is trying to portray at that point, so he improvises. That's fine. If the other players don't like the way the rules were applied and don't feel that they support the fiction the way they would like then they SHOULD be able to speak up. If the DM is going to try to be authoritarian that isn't a game system issue at all.
I never said otherwise. This entire paragraph is irrelevant and has nothing to do with my post or anything else said here.
The problem with a system that tries to work the way 3e's cover 'system' did or which just names some terms but never defines them like AD&D did is that you are always having to negotiate with the DM what it all means. It is all just either an endless time suck or everyone just assumes the DM knows what he's talking about since nobody else has a clear idea what is what unless they ask about every detail on the map.
That's funny, because I'm playing in a game using the 1981 Moldvay Basic rules and cover is largely a non-issue and literally a non-time suck, whereas in 4th Edition games I've participated in, those "clear, concrete cover rules" have been more of a time-sink than most combats take in their entirety in the Basic game.

Funny how that works.
The main reason that AD&D worked was really because it was such a BAD tactical game that it just didn't matter. Now, admittedly, 4e is a more tactical game, which some will or won't like, but GIVEN THAT IT IS its rules are formulated in an appropriate fashion.
You're right. 4E is a tactical game, designed like a board game. AD&D is a strategy game, and designed more like a war game.
But, neither of those things have anything to do with the
roleplaying aspect of the games. And, that aspect is accomplished with how the strategy and tactical elements, as well as the real world cues we're bringing into the game (dice, character sheets, minis, etc...) impact the fiction, which is the roleplaying part.
And, DM judgment is
essential for a roleplaying game.