So in the case of the Pennsylvania teams in the "pure" division, they were actually state winners in 2 different divisions by size. The team that beat Santa Margarita is actually a smaller school, albeit one that won 4 straight state championships, and yet only got an invite/attended the tournament this year.
Calling the tournament a "National championship" is a bit misleading, because it's invitational, and private/prep schools are often as good/better. It's really very hard to get any sort of comparison of all these schools, given all the different leagues and teams. In the same PA league where the 2 PA teams came from, there is a "AAA" division that has many of the aforementioned private schools. So basically, you have Santa Margarita playing public school teams, but not the teams that would more closely match them.
Then of course you have your traditional hockey states like Minnesota and Mass. that have their own systems and so of course you don't see teams from those places represented at all.