By the mid-1990s the studio wasn’t really ready to make a Fantastic Four movie yet, but they didn’t want to lose the rights, so they hired Roger Corman to direct a Fantastic Four movie on a shoestring budget.
When Fox scored the right to The Fantastic Four, the deal with Marvel required the studio to make a movie within a particular time period, or else the rights would revert back to Marvel.
The point wasn’t to make money, or even release it, it was all a business decision in order to hold onto the film rights.