.It's also missing saving throws versus wands/rods/staves, hit adjustments based on armour, in depth grappling, prestige classes, kits, and monsters with feats.
I don't think "it was in Edition #" is a good enough reason to include a rules element.
With the exception of (organization-specific) prestige classes, none of the legacy mechanics you describe are reflected in the campaign setting itself. Magic item economics
are, and that makes a huge difference. When a later edition fails to offer mechanical support (or offers mechanical support many players find insufficient) for elements that are visible in the game world, it creates continuity problems for any legacy campaign settings and for new settings intended to support the same playstyles as those legacy settings.
Many players want each new edition to continue to (better) support the way they already play D&D, because their enjoyment of such is why they play in the first place. A new system's failure to (adequately) mechanically support elements visible in the game setting, like magic item economics, is thus far more problematic than simply (e.g.) changing the way grappling is modelled.
What exactly is that "something"? Because from my point of view that "something" appears to be blind faith - a false belief that because the rules come from WotC they are somehow going to be inherently better for one's own group than what one's own group can come up with.
Adopting official rules is easy. They're already there, and the only buy-in required from the players is a simple agreement to rely on the published work of an acknowledged authority.
Adopting house rules is harder. In addition to the time and energy spent to create the rules in the first place, the DM requires the players to buy-in to the specifics of the chosen solution. Each (usually tacit) request that the players buy-in to a new house rule uses up a variable amout of the DM's social capital, depending on the scope and impact of the house rule (and, most importantly, the tolerance of the inidividual players for houserules). Tweaking mechanics on the fly (ala "I know the rules say this, but let's run it that way, I think it would be more fun") is relatively cheap in terms of expended capital. Introducing new/replacement subsystems, particularly if they're written down (e.g. new magic item crafting and pricing) can be quite costly. That many DMs have sufficient social capital to make such changes without harming their game doesn't help the DMs who don't have enough.
In case that got too abstract, let me try to illustrate the same phenomenon with a more concrete example. Assume two tables playing some RPG. Both tables are using identical grapple rules. At the first table, these are the rules from the book. At the second table (in a different universe with a different book) these are house rules. Further, assume that these grappling rules are awful.
I assert that the players at the second table will be more dissatisfied with the grappling rules than the players at the first table. The reason is because at the second table, the players had to buy-in to the content of the house rules rather than just the reliance on a recognized outside authority. In other words, the players at the second table will be more dissatisfied because the DM who made the awful rules is present and not fixing the problem, whereas at the first table the source of the problem is inaccessible, making the continued use of the awful rules more tolerable.
I'd further assert that the difference in satisfaction can in some situations be significant enough that flawed official rules may be more acceptable than flawed houserules
even when the houserules are superior, just because the source of the flaw is closer to hand in the case of house rules.
Does my explanation answer your question?
