Better public schools=better students, no question.
And Canadian kids probably succeed in the NCAA at a far higher rate per capita than kids from other states (and Canada is really no bigger than a large state, in population terms-- i.e. right between California and Texas-- although without the many benefits of density).
The only downside of recruiting Canadians is that, because they don't pay much to go to school at home, they tend to cost more (i.e. they don't want to spend more than it would cost them to stay home). They also tend to expect higher academic standards, there being no truly bad universities, at least by U.S. standards, in Canada. Granted, there are only 3 in the league of the BEST U.S. schools; but, the spread from best to worst is nowhere near that of the U.S.