Facebook and Google don't log all of my keystrokes across my entire operating system. As far as I know, Google doesn't even log keystrokes within the browser.
Except logging your keystrokes across the board is not what Microsoft is doing. Do you realize how absolutely useless that data would be? They are monitoring search queries, specifically in Cortana. They probably do the same for auto correct instances. They aren't logging all of your keystrokes.
> don't log all of my keystrokes across my entire operating system
Microsoft isn't doing this either, they are monitoring your usage of Cortana/System Search and your selection of its suggestions (just like Google does for Google Now,) to improve their algorithms. This is really being blown of proportion. Reminds me of people freaking out about Palladium with Project Longhorn.
But reserving the right, or just saying 'Look, we don't know all of the cases where a programmer will say "and if the user corrects this, tell us we screwed up"' (for the optimist) is not the same as sending it all.