I don't mind when people don't seem to know much about mutants in these early stories. We've seen very few, after all, and they haven't done too much in the public eye yet. But as the stories go on and they keep on doing dramatically public stuff, it becomes less and less plausible -- which, of course, is why more and more people have opinions about them. So I guess I don't have a preference, but I'd be baffled by a later book that tried to go back to early attitudes without using a flashback to do it.

I really like the parallel you draw between Nightcrawler's experience and Colossus's, here! I hadn't thought of it that way, but it's very true.