I can't speak for these nerds or their reasons for not liking the changes made to these characters. For me, these are characters from comics that I grew up reading, so changes to them in pretty much any form is rough to handle. A change to something as basic as their race is just Hollywood pandering for more ticket sales.

Why is it ok to change white characters to black, yet they have white guys play Asian characters? I think it is a double standard to say one is ok or else you are racist, but the other isn't a problem because Hollywood is just trying to appeal to a wider audience.