I'll comment on the Steelers:
Pittsburgh has lost a big chunk of its population, so their fanbase is spread out across the country.
I get that, and I get that people who actually LIVE in the area root for the team, but being in the next state over, there are just as many Steelers fans as there are Bengals/Browns. Seems very bandwagonish, and I bet half/most those people have no ties to the area. They just like to align themselves with a winning product. I'm SURE they all like the Pittsburgh Pirates as well