Yep, this is the #1 reason I still have a FB account. Until recently, I needed it so I could use Tinder. I have a great gf now, but just in case that fails, I'll want to be able to reactivate my Tinder account, and I need my FB login for that.
The only other reason I have a FB account is so I can be "friends" with some family members and some other people, because they use it. In practice, however, I never actually look at anything on there unless someone tells me "I sent you a FB message about such-and-such!".