I think many of these bugs are major enough that employers would want them fixed (e.g. not respecting ABI on Windows). A lot of effort has been put into LLVM’s optimizer and code generators so presumably this is something they value.

They track regressions in compile time and other metrics like instruction count for a bunch of benchmark programs on https://llvm-compile-time-tracker.com

That’s a popular trend in video games, too; quite a lot of people invest a second hobby’s worth of energy into their complaints, with the occasional gem in the rough among them. You can find this in any hobby - like, I know nothing about golf, but I am absolutely certain if I asked a golfer “what changed in golf clubs recently? are you still happy with them?” I am near-certain to get a lengthy spoken history of club design and manufacturing flaws. Humans are most irritable about their most favored topics.