You're entitled to your opinion. The cast wasn't why the movie was horrible, as much as you want spin that nonsense. I know what you're actually trying to say, btw (oh noes! Johnny Blaze is the wrong color, so the movie is going to be horrible because of that). The continuality was off, the production weak, the story sucked, and Dr Doom was horrible. A better story, and direction could have made this film much better.
I don't have a problem with them casting Johnny Storm (not Blaze) as black, but it forces the writers to drift even further from the original comics by having to complicate his relationship as the black brother of a white sister. I think if they wanted to cast a black man as Johnny Storm, fine. Probably should have caste a black woman as the invisible woman. I'd have been fine with that.
But Jordan doesn't really pull off Johnny Storm like Chris Evans did. Not because of race. Chris Evans was just a better fit. I think overall the cast of the 2005 Fantastic 4 is stronger than the 2015 version. Except for Michael Chikilis as The Thing. I just don't think he pulled it off all that well. I do think that this was more an example of an utter failure of everyone involved. Probably a better director and better writers could have made a better movie with the same cast, but an excellent cast would have made the movie better than it was.