One of the biggest reasons the original Deadpool film was such a huge success and earned Fox such a ginormous box office return was because Ryan Reynolds worked his butt off to ensure it was as Deadpool-ey of a movie as possible.
That meant violence. It meant gore. It meant sex and inappropriate jokes and a lot of breaking the fourth wall.
Now that kind of thing might seem like a movie producer's worst nightmare. Major motion picture studios looking for the highest rate of return are allured by family-friendly, safe cinematic choices. The more mundane and mediocre and inoffensive a film is, the more guaranteed of a return of investment, statistically speaking.