Prince was just a really bad evaluater of talent on the defensive side. He recruited some good offensive players and won some recruiting battle at times but if you look at what he did on the defensive side it was beyond awful. He also did himself no favors by hiring a buddy who was in way over his head to coach the o-line.
That's really simplifying it, but yeah, that's pretty much the gist of it.
Prince could recruit offensive players well (he did have an eye for them), but he had no clue how to run a defense and no one that could coach a defense (or most position groups for that matter) wanted to work for him outside of Franklin and Morris, who promptly left ASAP.
Pan, besides bad coaching what do you think CK's game would look like if Prince was still here. Well lets just say still his coach.
I think he would have moved to a different position because he wouldn't have fit what it was Prince tried to run, ultimately.
I think Prince valued dual threat because in his last couple of years, Freeman did run some. I think Prince would have tried to adjust the offense to Klein's skill set (if he were the best QB on the roster), but a lot of what Prince did with Freeman wouldn't have worked. The offense was expanded under Freeman with a lot of deeper crossing routes, out routes, etc. that he had the ability to perform and Klein simply doesn't have the arm for. A lot was open underneath for Freeman with guys like Banks because you had to respect his ability to throw the deep ball that simply never would have been there for Klein.
I'm going to guess that Prince may have spent a lot of time trying to work on Collin's mechanics, as well, so he may have looked completely different. That's hard to say. But would Klein have had the success he's had thus far under Prince? Probably not.
One thing that Snyder does well is protect his quarterbacks from their weaknesses. Thus far, he's done a pretty masterful job of doing that with Klein. Prince wouldn't have done that. He would have pushed Klein to do what he wanted as opposed to pushing the offense to do what he has the ability to do.