That is because MS is a marketing company, not a technology company, and they have buffaloed the general public into believing that they innovate, when in reality they just make poor copies of other firm's inventions.
That's not quite fair. Granted, Lord knows I've accused Microsoft of failing to innovate, and either buying or stealing other's ideas, but that's not ALL they do -- they have come up with some really innovative things in years past.
The problem has been that for the past 15 years they were run by Steve Ballmer, one of the poorest tech-company CEOs in history. He was a Sales guy, and all he thought about was consolidating MS's grip on the enterprise by way of the Windows monopoly. He was blind to the idea of doing anything truly innovative. Which of course is why every third word out of his (and Bill Gates') mouth during that time was "innovate". All lies.
But don't give short shrift to the brilliant engineers and other tech people at Microsoft. Given an opportunity they will rise and shine again. I think they will eventually get there with Windows 10.
Stumbles along the way are unavoidable.