Good points. As others have said, I'll probably move off later on, but for now I intend to stay with them (similarly I've been with Gmail for a while and now moved off to stuff like Fastmail, hosting my own "dropbox", etc.).
Primarily because for beginners it's a bit easier to setup everything without much hassle.
Look a few years back and you’ll find similar enthusiastic comments about Google: they make everything better and for free. Everyone should use their search, everyone should move to GMail, etc.