Whistler and Blade got more development than most of the X-Men, and they were playing the two of them being "Tough Guys" right down to the hilt.
I'm not saying that the "X" films up until now are a complete disaster, but you got to be able to take a reasonably realistic look at the films.
Just take Peter/Quicksilver. Can you seriously watch those films, and tell me that the character go the development that he should have? That he isn't literally inches away from being an entertaining 3D doll?