There aren't that many "finishers" to begin with, even in the NBA. Since anyone who shows any real NBA-quality scoring ability in college goes pro at the end of the season, in any given college season you've got 300 teams with maybe two dozen players total between them with any real talent for getting themselves to the rim and scoring, and half of those guys are raw freshman who spend half the season figuring out how to put their shoes on. I doubt college players shoot so many jumpers because they want to; they shoot jumpers because the vast majority of them aren't skilled and athletic enough to do much else.