Here's the problem for Fox, and I'll use Ant-Man for a comparison because it's been brought up before.
Two productions that have been controversial (for somewhat different reasons), and both going in directions away from the source material.
Here's the big difference though. Fox has given people ZERO information to change their opinions, which have been overwhelmingly negative. Whereas Marvel has opened up the book, and even created a fun spot for Comic con, even though it wasn't footage that was going to be used in the film. All of the actors have been very vocal about the project, and Peyton Reed has been an open book, especially with the departure of Wright and the scrutiny.
With FF, you can not get more polar opposite than that. It's been an absolute PR disaster that Fox has pretty much ignored. The only thing we've gotten is some bad leaked material on set, where it was all green screen, so who knows how it's going to look, other than Doom looks like a cross between a mummy, a Dark Elf, and little red riding hood.
For those saying, "I'll wait until they show me something before making a judgement," you should be asking, what's up with them not showing anything?