While I agree in very large part with your first paragraph, I will make the observation that there is so a lot money bet on the NCAA tournament that is really, really dumb money. Just stand in line at a Vegas sportsbook during the first Thursday or Friday morning and you'll hear some of the craziest theories, not to mention the fans just betting on their teams. That kind of behavior creates opportunities in certain games.
But, yeah, 300 games per week certainly lends itself to a few soft lines more than the NCAAT does.