I guess employees are compensated with stocks from the for profit entity. And at the face value before the saga, stocks could be like 90%, 95% or even more of the total value of their packages. How many people are really willing to wipe 90% of their salary out? Just to stick on the mission? On the other hand, M$ offers to match. The day employees are compensated with the stock of the for-profit arm, there is no way to return to nonprofit and their charter any more.