I think natural selection is also a factor. Probably you are right that incompetence is more or less evenly distributed, it's just that only organisations with a lot of money can survive using MS stack, by pouring money on a problem. And you can be on the receiving side of it.

Plus, few competent people like working on it, they prefer sexy open source things, it means it's easier to stand out.

Hardly a way to have a happy career, but surely a way to have a happy (and early) retirement.