Just my experience, but there are just d-bags everywhere. Buffalo Bills fans are not excluded from this phenomenon. I’ve been to away games in Miami, Charlotte, New England, San Diego, and Seattle.
While there are differences between places, I have found that 98% of opposing fans are generally kind and respectful. There’s the occasional good natured ribbing, but that’s part of the game day experience for a visiting fan.
Then of course you have the 1-2% who are idiots. You’ll have that anywhere. I will say, however, that the ones with the loudest mouths are typically the ones who are the least knowledgable about their team. I can’t prove it...I just know it to be a fact ?