I don't know if Kitty Pride is the problem. It would be pointless with the X-men movie continuity to do that. Part of the original is that Kitty is an extreme newbie in the present and gritty person in the future. So it's crazy for this to be happening to her. The movie timeline didn't really set-up that or really do anything with the Kitty beyond being Iceman's new love interest. So I don't even know what they could do to all of a sudden have her be the new lead. Wolverine works better as the lead.
Also there's no point of introducing Rachel. Movie had too many characters as it was and couldn't do much with the new mutands already.
My problem is that the future X-men/mutants are the coolest thing in the movie and have the most interesting dynamics. Be it just thier current situation or the way they battle. The movie does nothing but kill them off. Instead of it being like the original story where the future X-men actually do something, they just sit around and then die. Kind of a waste. The future is hardly seen and half the fun of the orginal story was getting a cool window into the dark future. We don't really get that.
No we're left with Jenfier Lawerence who sucks as Mystique. Mystique is a spunky and cunning female character played by an actress who's never played that character. katniss may be a tough, smart, and resourceful, but she dosen't do any of that with a sadistic smile. So she's kind of boring to watch, unlike Rebecca Romijn who was actually good as Mystique. She may not have been the leader in the past movies, but she still had that cunning spunk attitude.
The problem is the movie is centered around boring and crying Jenefier Lawernce and the battle for her, which is'nt interesting at all.