I think I sense an "agree to disagree" moment coming, but I'm going to try anyway.
I feel like that proves my point.
Nonbelievers get married, and by and large they get married for the reasons I cited. However, you agree with me that this doesn't mean we (Christians) shouldn't get married.
Why?
It boils down to the simple fact that we view it differently (read "get married for different reasons").
IMO the same principle applies to tattoos. Just because society uses them as a way of rebellion, pride, or sensuality doesn't mean that a Christian with a different view of them shouldn't get one - just like a Christian shouldn't stay away from marriage because of the way society uses it.