A view from my small corner on the inside: taste isn't merely not incentivized, it's actively disincentivized. It's not selected for during the interview process, if you demonstrate a little of it nobody cares, if you demonstrate too much of it you clash with everyone else's priorities which quickly becomes career limiting. So people willing to fight for taste never advance.

This isn't some nefarious plot to screw over users. Taste is not prioritized because nobody has it and thus can't recognize it. Can't value something you don't even recognize. This is orthogonal to talent btw. Lots of people there who are insanely good at what they do, who produce the most hideous API specs you've ever seen, as one example.

A much more mundane (and almost certainly true) explanation is that people who put all that crap in legitimately thought it's a good idea. Taste is its own thing and it's just not in Microsoft's DNA.