Earlier quoted context omitted.
I think it's simpler than that. Unpaid developers overwhelmingly prefer to work on the intellectually "sexy" problems such as encryption or compilers, to the detriment of the boring-yet-important stuff like UI improvements and hardware compatibility (let alone proper QA).
I think developers and most users simply don't even notice the problems. When I say "I can't use program X because the UI/UX sucks, is there any alternative?" people come out and say "I see no problem with program X, I use it everyday and it rocks"
You've got strange conclusion out of it.