20The director of the original movie was fired
This made it shocking when director Tim Miller did not return for Deadpool 2 due to creative differences with star Ryan Reynolds over the tone of the sequel.
The original Deadpool was a somewhat unlikely box office hit. The character was not as well-known to the general public as many other Marvel superheroes, the movie wasn't an official part of the MCU, and it was distinctly R-rated, featuring profanity and very explicit violence.
Nevertheless, it went on to gross $363
million in North America and another $420 million overseas. By all accounts, it was a global blockbuster.
Once a winning formula has been hit upon, it's rare to see the core makeup of the creative team changed in any way. The presumption is that bringing back all the same people will help catch lighting in a bottle a second time.
Specifically, it was rumored that Miller objected to the casting of Josh Brolin as Cable. Rumors also indicated that Reynolds and the other producers wanted something that felt similar to the first film, whereas Miller wanted to make it substantially more epic, and therefore more expensive.
When asked about the departure almost a year later, Miller said that he was relieved to not helm another Deadpool adventure because he felt that it would merely be repeating what he'd already done. He added that he was eager to tell different stories.
Whatever the reason, Miller and Reynolds, pictured together above, at least collaborated on one well-received movie.