Right, I agree, pretty much entirely. The problem is there's a hard core group of D&D fans out there for whom anything that isn't in the 1e core books is going to be anathema and no amount of saying "this is just as logical and more playable than what we had before" matters one iota.
If it was a DETAIL of the system, like this or that feature of a class or how some terminology is used, or even what magic system you're going to use it isn't really a drastic big deal, we can do things different ways.
The problem is hit points and healing aren't some tack-on aspect of the game. How hit points work and what they mean (see below) is the single most core thing in the game. The one thing that is absolutely shared across virtually every aspect of the game and which must be consistent if you are going to have a coherent game. ALL OF THE RULES need to be able to rely on the fact that "10 hit points of damage" means the same thing in order to make sense. If that's a scratch (for some level of PC) then it needs to consistently always be a scratch, and if it is a highly damaging or lethal wound then it always needs to be that. How you can recover hit points and manage them also MUST be consistent for the game to be coherent.
In other words there is one way that hit points can work. There can be SOME small variations, but the core meaning of a hit point and the ways it can be managed by the players during the game is not something you can plug in and out with a module. It is the foundation of the house that everything else must be built on.
Of course I don't know where WotC is going to come down on this, but more than any other aspect of the design of 5e it is the breakpoint. Most everything else that I value about the way 4e plays stems from its approach to resource management. There's simply not any way that 5e will play in the way that I want built on top of AD&D style hit points. Likewise we can clearly see that many other people aren't much interested in that. I guarantee you this will be the breaking point for acceptance and non-acceptance.