As funny as this sounds a couple years ago there was this local guy who had some connections to junior teams in the western part of Canada. He came out to watch my son's high school team play a couple times, I had spoken with the guy over the years so I knew him a bit. He was looking at one of the defensemen on the team, the kid was totally under the radar, liked playing hockey and was just a quiet kid but good at other sports too so he had some choices. The kid might have been one of the best 2-3 high school defensemen in the region, so the scouting guy goes up to the kid's dad and says, "call me when your son hits 6'3 and then I have a spot for him on a team in Canada" (at the time the kid was maybe 6'1") "I have direct orders that I cannot bring the team any defensemen under 6'3"." The kid ended up hitting 6'3" or 4" but didn't have any interest in playing college hockey but that is how sized crazed some teams are.
"...you can count the number of Mass U16 defensemen who can make a tape to tape breakout pass on one hand."
That's good because there are about 10 kids that can actually catch a pass that hits them on the tape! $200 sticks and the puck bounces off them like they have springs in them.
I think it's a lot of smaller factors. One is, hockey is THE sport in the state. And as such, it attracts more and better athletes than our pool here. Two, having lived there the hockey culture runs deep and the level of coaching at the youth level comes from some of the best hockey guys in the US. Also, every park has an outdoor rink or two or three where the kids can play for hours a day - similar to what may have been here years ago. And like here, the kids from ex-players are given a leg-up to get into the family business and they just have a lot of ex-players. The interesting thing in the upper Midwest is they're starting to get the pull into 'club teams' but it is rare that a kid feels the need to spend the $. Midwest sensibility trumps the need to buy their way toward their dreams.