It's their own fault for letting it go as far as it did before realizing what it became. Stepping up Thing's appearance to a cgi look, giving Doom his comic book portrayal, and casting actors who look older than 15 yrs of age I thought would've been obvious starting points for a retool. Gathering some classic FF comic arcs and picking the most feasible one(s) to adapt again, while assessing all that went wrong in the execution of the previous two films (from critics and fans) would've been the next logical step.
But i guess the director must have gave em one hell of a sale's pitch or sold em the wolf ticket of all wolf tickets to have them think pushing aside any likeness to the actual franchise outside of the title and character names wouldn't be an unnecessarily risky (at best) if not down right dumb idea.