Remember Milestone Comics? I remember a funny story about that. A young black kid walks into a comic store and the store owner points him to the Milestone Comics, Icon, Static, and all the rest. The black kid responds "@#$% that! Where's my Spider-Man?!?" Being the same skin color as you doesn't make a character automatically more appealing, as was the case with the Milestone characters for that kid. And plenty of black Fantastic Four fans would rather see the Fantastic Four they know and love rather than a cheap knockoff in a pathetic attempt to pander. Nevermind that, if you weren't already interested in seeing a Fantastic Four movie, then I doubt a black Human Torch will suddenly make that franchise more appealing to you, so it probably won't bring any box office benefit. It will, however, piss off a segment of the fan population who want to see their beloved characters on screen, not bastardized versions of them.
Would it be nice if there were more superhero movies with minority characters? Sure, but how about promoting characters who're already minorities instead of pissing off a segment of the fans right from the bat by messing with long standing and popular characters? War Machine, Falcon, Black Panther, Bishop, Prowler, Luke Cage, Blade, Rage, Night Thrasher, Cardiac, Blue Marvel, etc. How about promoting those characters? That's something which every fan would be glad to see.
Even their powers, personalities or names aren't what make them special or are inherent to their characters. 
What? a) this is not the first black superhero on film and b) I'm fairly sure all the young black children probably want to do the same thing the other children want to do when this movie comes out: go to the new Pixar movie.
