It's something of a fad, or a cultural thing among adolescents and the under thirty crowd. I have no idea where it came from, but it's an epidemic. I even hear it here in Texas. The kids pick it up from one another. Sort of like the Valley Girl affectation back in the 80s.
It's disgusting. It's a namby-pamby, homo sounding lilt. The young guys don't even hear it in their own voices, but they sound like prissy little poofters among normal men.
Makes me really glad I live so far away from - well, anything!