I can live with spotify having facebook integration - I'm sure there are people out there that like it.
I don't mind the ability to sign in with a facebook account; letting people have one less username/password to remember is a noble goal.
I do mind how new accounts require a facebook account, but I'll let that lie for now.
But don't send me mails nagging me to connect my spotify account to my facebook account. There's a reason I haven't.