Why can't people keep their college allegiances separate than the NFL

Why can't people keep their college allegiances separate in regards to the Steelers?? Pitt guys aren't rooting against Pat Freiermuth and Allen Robinson for being Penn State guys. West Virginia center Zach Frazier is good enough to be a serious option in the draft. Do people really root against Pickett because he went to Pitt? We think a few might have a bias, but pro Pitt people also have a bias towards him. Mike Tomlin has never had a losing season. What is considered a successful season?