Steelers fans are not the most hated fans in the professional sports. That title tends to go to teams in the northeast on the Atlantic Ocean. I don’t what it is about cold weather and salty water but fans from Boston, New York, and Philadelphia are typically the most hated across all sports. Eagles fans hold the title in the NFL. That being said, in the NFL, Steelers fans are up there at least for some especially.
Especially if you grew up in Steeler country, Western Pennsylvania or a radius of a couple hundred miles around it you get an earful from those who aren’t on board.