Mutants can be bigots, too. Especially the hotheaded Pietro. He’s consistently been portrayed this way, too. See especially Peter David’s writing in early issues of X-Factor. Great, great stuff–best Quicksilver comics ever.
Note: This issue was continued in Fantastic Four #150. Unfortunately, I started blogging on F4 a month after I started on Avengers, and I haven’t been able to catch up yet. So, we won’t be tying them together. Anyway, this panel speaks for itself. No need for continuity.