One of the things you have to realize is that a lot of the dynamics of the company over the last decade have caused a mind boggling amount of talent to simply evaporate out of the company. Many of the "fuck you I'm fully vested" folks who were around in the earlier days of MS either checked out or peaced out whenever they hit their personal bullshit thresholds. More recent hires have generally found that other companies are often more exciting, more rewarding, and more lucrative to work at. MS today tends to punish caring about things (not always, but more often than not). If you try to make a difference and put forth the effort to make merely sensible changes then you'll spend years struggling against the system and if you're lucky you'll only have moderate success to show for it.
And the stack ranking system tends to reward people who are good at gaming the system rather than those who are good at actually delivering anything of substantive value to end users.
Naturally, all of this tends to be very discouraging to engineers, especially those with a bit of maturity and experience who see that with their talent and skills they could go elsewhere and not get shit on all the time, work for a company they wouldn't be embarrassed about, and actually get stock options that are worth something. And, since techies tend to value working alongside other techies that they admire and look up to this sort of process tends to be a positive feedback loop.
It's simply unimaginable that this loss of talent hasn't had a huge impact on the company.