Don't quite agree with this. IMO, they do have better players than the teams they've beaten over the years. But not necessarily better athletes. If NDSU has done a better job recruiting than the Gophers, for instance, it's because they have done a better job seeing the difference.
It's worth noting that none of the players mentioned as examples of NDSU supposedly benefiting from poor recruiting at Minnesota were recruited by any other Big Ten teams. If Brewster, or Mason, or Kill were all wrong so was every other coach in the Big Ten.