Is it really a matter of choosing not to recruit outside of Minnesota or, for the most part, not having to? There are so many strong hockey programs throughout the state they don't necessarily have to leave the state for recruiting purposes if they don't want to. There are a few exceptions, though. Vanek, as already stated, and the Potulny brothers.
The fact is, all teams recruit from all over. It's not like UND is the only school to ever recruit outside their home state. Everybody wants the best players that are the best fit on their team. To use "out-of-state recruiting" as an argument about why UM is superior to UND is just grasping at straws.