You'd be surprised. There are many of us who don't do social photography and use desktop photographic software and Windows' built in image management stuff.
And Microsoft make more money out of us with Windows licenses than Facebook do with social photography.
The right client bet was the choice of doing it where you please, which they offer(ed).
However, they're pushing everything onto SkyDrive now in an "everything everywhere" approach which is a bad move.
Surprisingly Apple and DIY (Linux or own software) are the only people offering choice still, or at least not nagging you about moving to the cloud.