I get the impression that there are other people who see the imperfection within an RPG that often necessitates customization to smooth out rough spots to be a feature.
"Bad rule make games good!" Could've been the motto of WWGS (one of their guys is reputed to have said something like that). Ironically, it /also/ could be the motto of D&D. ...ironic because Roll v Role... 90s? UseNet... ? ...it's ironic if you're old enough to remember the September that Never Ended.
I'm not sure if there is a different purchasing intent--ie, desiring purchasing an RPG to provide a similar experience to purchasing some sort of do-it-yourself kit.
We'd all be playing Hero/Fuzion, GURPS or FUDGE/FATE, if that were the case.
Now, I know some of it relates to people that got started a few years before me when you almost couldn't buy an RPG product that wasn't overtly and unavoidably riddled with inconsistencies that made it literally unplayable "by the book"
So sometime in the last 45 years?

OK, no, I get it. Really, even before the fad catapulted D&D to grudging mainstream name recognition c1983, some basically functional TTRPGs had rolled out.
If one's foundational experiences were with being required to "fix" a system in order to play, it might be understandable that us kids today wanting a system that works "out of the box" is just entitled nonsense (j/k).
Prettymuch.
Now, maybe that's the only demographic that feels that, in which case it makes sense. I just wonder, if that's not the case, in the case of more recent players, why there is so much more of a tolerance for RPGs that don't work or are inconsistent without customization, than for other forms of entertainment.
The thing about a hobby that stayed as small and insular as ours did until just recently is that the first cohort to dig in retains outsized influence, and thoroughly indoctrinates the new recruits into their inner mysteries.
Now, you might think that now that D&D has had it's come-back and followed the general TT renaissance into the mainstream that such will no longer be the case. But you reckon without the darksome power of our vast conspiracy! (OK, that's overselling it.) But thing is, when 5e was being designed, it still had to appeal to our
cultniche market, at least be acceptable to it, so it /is/ exactly what you don't want: a classic car of an RPG that you must Fix Or Repair Daily. ;P
And if you really, really don't like that, well, you won't stick with the hobby, will you?
And the hobby will just stay this way.
::Ursula voice::
Forever….
::Villain Laugh::