I know there are a lot of people like that, and I know it's probably what people think straight away when they hear someone complain about let's say Sam being Cap now, or the new female Thor.
Now I can't speak for everyone of course. But I can assure everyone here that there is nothing racist, sexist or anti-LGBT in me. They would have given the Giant-Man suit to a Scandinavian albino that I would have had the same reaction. If they had kept Steve young and active, let's say as Captain Rogers, I wouldn't mind FalCap. If Thor was still worthy, I wouldn't mind the female Thor. If Hank Pym was still alive and doing heroics, heck I wouldn't mind if there was another Giant-Man... Okay, I'll be honest on that one: I wouldn't mind as much
My point is I like the original characters. The fact that their 'replacements' are of a different gender, ethnicity or orientation is irrelevant to me. That's not what's bugging me. What bugs me is that I don't get to read about the characters I like, except in old trades.