Like I said, people aren't dogs, they're not going to go for it just because you tossed a few new things at them. These people really don't think much of the audiences they make films for, do they?
Adding characters wasn't enough...? It's called
writing. Did we forget that was important in film making? And proper research that doesn't just skim the surface. Should have found a group of writers who in fact dearly love these characters and know how to write them well. Or at least writers that will talk to a diverse group of fans and pull knowledge from conversations with them; esp discuss each person's fave character. (And they don't just have the story fall flat at the end... At least as far as the whole villain plot goes. The Turtles were done better, that's all I can give it.)
They'd have really been better off skipping origins and fast forwarding TMNT in age and just coming up with a new story instead...
Edit: Basically a PD movie in 50 years (not that they'll still exist):