They can go to 0GB for all I care. I don't use SkyDrive, let alone any file sharing service (legal or otherwise). I see no point in openly sharing my stuff.
This isn't about "sharing" your stuff. You don't have to "share" your stuff with anybody.
Unless of course by "share", you simply mean put it on a computer that is not run and maintained by you. < - Many do have concerns about this and there is no right or wrong answer, it all depends upon the user.
I don't use any of these services for sharing with others, but instead use them as
1). Replacement to carrying around a USB key with me. As long as I have internet access, and the files I want are in SkyDrive, it's like having a 25GB USB key with me at all times.
2). Secondary copy of data that is in a location other than my home. This way if I am robbed and all of my computers are stolen, or my house burns to the ground, or my home floods and my computers are all damaged that I have a safe copy of all of my kids digital photos and such.
I've worked around my robocopy issue. I found that I can use Karen's Replicator to sync 2 directories and NOT use timestamps as a variable in determining whether or not to copy them. It will just use file size and file name..which is good enough for my purposes of having my own digital photos in a remote location.