Everyone else pretty much summed up my opinions on the matter. I'll just add Gambit and Storm.
Was there anyone, ever, who wanted a Gambit solo movie? No? I didn't think so. There is literally no reason to make this movie. On the other hand, Fox has one of the most popular female superheroes in Storm, who has a very interesting backstory which they could explore. But no. Despite being one of the most popular X-Men behind Wolverine, she's not going to get a solo movie until at least after we've already had three Wolverines, two Deadpools and one Gambit movie.
To be clear, I'm not complaining about the obvious sexism of having six solo movies about white guys before one Storm movie. I'll even say that Wolverine and Deadpool are even somewhat justified. Wolverine is the most popular X-Man and Deadpool plays better on his own than with a team. But there is no excuse at all for doing Gambit before Storm. No, what I'm complaining about is the fact that Storm is a great character, one that could have her own solo film, and she has been completely underutilized. Even in the movies she did appear in, she was never given any real development or character arcs. She was just a chick who shot lightning.