Alzrius
The EN World kitten
Looking over this, I think that you're outlining a point somewhat (not completely, but somewhat) orthogonal to the issue around hit points trying to model two different things at once.I agree with a lot of the other stuff you wrote, but I think this in particular is a bad example. As you rightly observe, the language around "hitting" in combat and individual attacks (especially missile weapons, which always ran contrary to OD&D and AD&D's one minute combat round and its premise that a given round and a single attack roll represented multiple in-fiction attacks), and of healing spells, was always sabotaging Gary's explanation of what hit points actually are. The latter was compatible with characters fighting and moving at full effectiveness no matter how much damage they take (until zero, anyway), but the game rules and language around hitting and damage and hit points always created this cognitive dissonance.
Ben Laurence did a great job articulating a lot of these issues in a blog article a while back.
I might also suggest that hit points are more of a narrativist and gamist concept than they are simulationist. Like saving throws, the essential purpose of hit points is to keep characters alive, because a storybook hero doesn't die to one sword stroke (as a rule). That was the original reason Arneson put them in his game (when a player playing a knight was dissatisfied by being killed in a single round by a troll), and it's still the main reason D&D uses them.
IMO 4E did the best job to date of squaring the circle reconciling hit points to work better and make more sense. Particularly in its linking most healing to the Healing Surge, a value of (usually) 1/4 of a character's max hit points. This meant that we were finally relieved of the issue D&D had always had of "Cure Light Wounds" being capable of restoring a first level character reduced to zero HP unconsciousness (seemingly a serious wound) to full health. And the issue that a low level character or low-HD class like magic user healed more quickly from injury than an experienced character or a combat-trained one who is inured so pain and injury. By making healing proportionate to the character receiving it, 4E made hit points a little less nonsensical.
I think you're right, though, that the overall changes to the hit point system were a bit too much for a substantial percentage of players who had reconciled themselves to the contradictions of D&D's hit point system and didn't want to think about them anymore.
Now, hit points are very much gamist in function (though I wouldn't say simulationist; while I won't speak to how Ron Edwards used the term, my conception of it has always been about mechanics that set/affect the narrative directly rather than mechanics that happen to abet dramatization), which is why I previously pointed out that they were an area where simulationism backed off. That was, as I posited, a consensus (or maybe I should have called it a compromise) that everyone was unhappy about, but could live with.
But while the issue of scaling wasn't necessarily limited to healing spells being less effective as a character leveled up (that was just the inverse of the aforementioned issue of how the same 8 hit points' worth of damage in one attack could kill a commoner outright, but meant little to a high-level character), 4E's attempt to fix that by having a central healing mechanic that operated on a percentage basis was a legitimately good idea...one that it completely undercut by leaning hard into having hit points (or rather, the loss of hit points) be a model of being progressively injured until your life was in danger and simultaneously being a model of progressively losing combat capability.
While there was a modest amount of conceptual overlap in those two metrics, they were still dissimilar enough that they caused a cognitive gap for a lot of players in how a given solution (i.e. a warlord yelling at someone to let them use a healing surge, a cure light wounds spell, etc.) functioned for both – since, again, it was a single mechanic modeling two different things at the same time – despite being presented as a fix for only one of those two things.
The result was that the percentage-based healing solution was presented as part of a much greater problem. It was like finally fixing that leaky faucet in your bathroom by ripping the entire sink out of the wall. Sure, it no longer leaks, but now you have a big flippin' hole in the wall gushing water everywhere. The solution isn't going to be well-received at that point.
Little things like this came up a lot with regard to attempts to tie abstract presentations to mechanics that lent themselves much easier to singular, well-defined instances of play. For instance, the idea that attack rolls represented a non-specific flow of back-and-forth attacks, feints, parries, etc. over a one-minute course of combat seemed like a nice idea...until someone was using a poisoned weapon. Now, the successful attack roll indicated a very clear, specific hit, since that was the method by which the poison reached your character, and all of a sudden the abstracted nature of attack rolls fell away.
4E had some good ideas, but between poor implementation and being overshadowed by bad ideas, it managed to turn its strengths into weaknesses, and for quite a few people that simply wasn't something that they could forgive.