Development hell is a difficult place to escape from. Just ask Channing Tatum; the star/producer of Gambit has spent over four years trying to get that movie up and running since it was first announced, and the project is now looking for its fourth director after Rupert Wyatt, Doug Liman and Gore Verbinski all jumped ship.
There are so many ideas floating around Hollywood at any one given time that its an inevitability that some of them end up getting put on the back burner whether it be due to rights issues, finding the right creative team to bring the story to life or trying to cobble a budget together.
Plenty of movies have escaped from development hell over the years with varying degrees of success; Ryan Reynolds' perseverance turned Deadpool into a box office juggernaut, Warcraft became the highest-grossing comic book movie in history and The Dark Tower... is a thing that exists.
Being stuck in development hell isn't the death-knell for a movie (well, apart from Superman Lives), but plenty of projects have nonetheless found themselves trapped there for a very long time. Whether or not they were worth the wait is a matter of personal preference, but spending so long in cinematic limbo often results in a very different movie than what was originally in mind.
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