True. But as many people here complain about the hp system in DND, I would imagine there are many, many more who are fine with the way it works--its just a game, really.So do we, but it's not something one can dream up on the back of a napkin and not every DM is willing (or able) to do the designing required to make up such a system that works well enough to play.
That, and as the RAW say it's supposed to work in a particular way that's what players come to expect. Much better if the RAW included a physical damage component to set expectations, and leave it to individual DMs to strip it out if they want a simpler version at their tables.
Think of all the things people have added over the years, both by game designers and homebrew:
critical hit tables
and so on...
Yet despite this, with each new edition we don't really see much change in how hp function in the game. Now, I can't speak much for 3/3.5E since I played it less than a year (and over a decade ago!) or 4E since I never played that. But judging from what others have told me, nothing changed that I am aware of.
With all the other variant options in the DMG, something would have been nice, but even if they had, I am afraid it would not have been enough to make those who wants something happy.