I've finally got around to write at least the start of a more detailed answer and that casually named "practical approach" of mine turns out to have quite deep and far reaching roots indeed.

I still haven't quite figured it out but as an updated attempt, I'd say it's because of being stuck in a world full of shallow people unable to perceive or care that a mess even exists and thus to do anything about it.

To try and clarify perhaps a bit my view on the matter there, I'd say that there are essentially two failure modes and arguably it all comes back again to that extreme polarization/lack of a middle ground (i.e. it's not that these extremes haven't always existed but simply that nowadays the middle ground seems to be nearly extinct or in any case not all that visible, perhaps especially so in programming): at one extreme, those perfectly able to perceive and care about the mess taking a fully ideal rather than a practical stance and getting as a result stuck and not doing anything about it because the ideal solution is not yet possible or producing otherwise some monstrosities that are theoretically ideal and practically unusable/unjustifiable as costs; at the other extreme, those just "wanting to make it work" who just fiddle with it until it appears to be working and producing as a result only more complex problems (if, at times, delayed) that are nevertheless easily sold as "solutions" (and the nasty part is that this approach is very easy indeed when done to something that was made initially correctly, basically riding on that underlying correctness and only gradually sinking it, thus being able to deny for long enough any responsibility for the sinking).

Balancing acts are possibly always just about the hardest to get right and it's also quite usual that anyone trying to walk that path gets arrows from both camps above since they are "in the wrong" from both perspectives: for the purists of the high ideals such balancing is dirty and at least at times "being a hack" (and nevermind the whole) while for the shallows of the fiddlers, they are just incomprehensible and at least at times "uselessly complicating matters" or "being unreasonable" or some such.