Being a superhero movie means everything! When was the last major superhero movie that made less than 300 mill? And the previous Fantastic Four movies left a bad taste in peoples mouth primarily for comic book fans, and even than I've met some who've liked it. And be realistic the movies weren't necessarily a bad representation of the FF. Weak script and for some dull performances are to blame honestly.
And go back and look at the hate for Transformers 4, now go back and look at how much the movie made. Over a billion. That argument becomes less and less valid.
Hell, go look at the doubt factor for Days of Future Past; which ended up being one of the best comic book movies ever.
A trailer or two will get people excited, or at least curious. The only reason this movie is getting hate in the first place are because of the deviations which result in people blatantly ignoring the HUGE talent from both cast AND crew. I'll reiterate, this movie will go under the radar and become buried in hate that more than likely it's going to become a huge hit. It's been happening often.