Can you explain how you think the 4e rules are lacking in regard to these things and where you think another edition of D&D has devoted more attention to them or done a better job supporting them in the rules? Because I'm just not seeing what you are seeing.
I can't speak for anyone else, but IMHO speed of play is a real issue, in all WotC editions of D&D. If an average combat takes X time in the real world, and an average session lasts Y time, then X/Y determines the number of potential combats in the game.
Should the potential number of combats be very high, because combats play quickly, then there is more time in each session to devote to traps, tricks, exploration, role-playing, etc. Nobody feels gypped that this material takes away from bopping some orcs on the noggin. IOW, the weight of a satisfying session is balanced among many encounters, so each can be its own thing without dragging the whole down. Like wearing snowshoes.
However, if X/Y yields a very low number, then the weight of a satisfying session is balanced on relatively few encounters, and each encounter must be that much more capable of supporting a satisfying game session by (or nearly by) itself. Like wearing stilts in deep snow. In a game like D&D, this often means combat encounters, at the expense of all other type of encounters.
A low X/Y also means that these combat encounters will often fall within the same "threshold". If it takes half a minute to defeat a giant rat at 10th level, the 10th level character may well encounter a giant rat without thinking it a major waste of time. If it takes 20 minutes, though, things are different. This is why "combat grind" in 4e becomes a source of complaint.....Or why many high level combats in 3e become dissatisfying.
(IMHO, this is the direct result of pushing a grid-based combat system; itself a direct result of WotC's marketing research, which pointed out that a gamer who buys minis tends to spend over 40 times the amount of a gamer that does not.)
RC