I guess it makes some sense. Magic's too out there to add to a Sci-Fi movie, so they go with electrical powers and TK/TP. McMahon wasn't a bad Doom, he just needed more material. As for Trank, he had a meltdown on 4chan once and spilled some beans, and storyboards and the such have surfaced since the flop. And from what I saw I think he would've delivered a great body horror/Ultimate-esque Trilogy. But between studio meddling and him being a jerkass, we got what we got. Still, I remember reading a bit from an early draft where they go to some dead planet. They look around and it's all destroyed, grey, everything's dead and bodies are everywhere. They keep going and reach a massive amphitheatre of sorts. They start exploring as something slithers in the remains, and eventually the whole thing starts shaking and Galactus reveals himself. That's a pretty terrifying scene if done well. The problem is that it makes little sense for Galactus to just be hanging around a planet he got done consuming, so I'd change it a bit (I used to have a headcanon about my own AU that merged Galactus, Gah Lak Tus and the Celestials). But the point is a more serious, space horror-esque FF can work. Should it be that? Most people would dissagree.
Personally, I've always seen F4 as a pretty versatile property so I don't mind breaking away from the mold. It can work as corny, family-friendly space exploration, as a tale of mad science, as cosmic horror, whatever. I might be one of the few people on the planet who liked the Evangelion homage one-shot from the defunct Marvel Mangaverse:
I think it's an IP with promise that could go in a bunch of different directions if you wanted to try more things with it. I think the same applies to the X-Men. And I've always thought Iron Man could be more than what he is. Most of the characters/books/franchises I still have an attachment to are ideas that I think are great but are not executed properly, and have given new life to them in my head. So I sort of project my own wishes on them, and the figures I want represent not only the source material, but my own idealisation of it.
