Originally Posted by LoathsomePete

Probably because it's embarrassing enough to not be able to make a good movie out of the property, but to give it back to your competitor who turns around and makes a hit just makes you look utterly incompetent. FOX executive heads would be rolling come Monday after Marvel's Fantastic Four breaks box office records and receives critical praise, so it's easier to just cover one's ass and pretend like what went wrong with the movie was something unforeseeable. Right now though, it's all about damage control, and it's bad enough when the film's director is slagging it off on Twitter the day of the release, but to have an executive come out and say "We're cancelling the sequel in 2017 and selling the rights back to Marvel" would be career suicide. News on it will go dark, FOX will focus attention away to Deadpool, X:Men Apocalypse and Gambit, and that June 9, 2017 sequel release date will be filled with something else, most likely X-Men related. I highly doubt that there will be another FF movie within the next 5-6 years and wouldn't be surprised at all if they negotiate a trade, Marvel gets the movie rights back for FF and FOX gets TV rights for the X-Men.

Originally Posted by J.R.R. Tolkien

There is only one bright spot and that is the growing habit of disgruntled men of dynamiting factories and power-stations; I hope that, encouraged now as ‘patriotism’, may remain a habit! But it won’t do any good, if it is not universal.