That's the old-school ethos for you, Gygax's best efforts notwithstanding: the rules as written are merely an adjustable framework and not necessarily even complete, that you then adjust (ideally, locking in your adjustments as you go!) to make the game your own. The rules designers are fallible. No two tables are the same, nor are they intended to be outside of organized play (the RPGA back then wasn't as relevant as AL has become now) or convention tournaments (which used to be a big deal but we just don't see them any more).
I agree up to this point.
That's the WotC ethos for you: the rules are inviolate, and not to be messed with. The rules designers are perfect (and if they're not, we'll fire them). Hardly a surprising take, perhaps, from the company whose roots lie in Magic the Gathering; but not a very useful one in the wild west that is the greater D&D community.
That's just it: the WotC editions - 3e and 4e in particular - want their rules to be binding straitjackets. As such, this leaves those rules more open to criticism because they've largely taken away the idea - and general acceptance - of "just fix it to suit yourself".
For 3e they did try to answer everything and in my opinion just added extra overhead that lead to endless page flipping. With 4e they changed the nature of the game to lock it down even more to the extent that for many people it felt like an entirely different game.
But with 5e they talk about the DM being in charge and house rules quite openly. They realized that what they had tried to do with their previous attempts didn't work and they went back to the older philosophy, at least to a degree.
TSR general principle: you can do it unless a rule says you cannot.
WotC general principle: you cannot do it unless a rule says you can.
For my part, if someone calls out a crap rule in 1e (and hell knows, it sure has some!) I'll just say how I fixed it, and hope others do likewise so we can compare our solutions.
There is more structure, consistency and in general more coverage. But people house rule things to small and large degrees, one of the things we discuss in games I run or play is what the house rules are. There are now entire third party books that alter the core rules.
It may not be as free wheeling as the TSR days, the game has changed and I understand why that doesn't work for some. But it's still "You csn do it if the DM okays it".