Doughnutman,
This thread regarding which metal bat to choose illustrates the chain of behaviors that leads to colleges being sponsored to use metal bats.
The main market for metal bats is the youth market, and players/parents want to get the "best" bat, which primarily means durable pop. So the bat companies make these bats, and of course they compete to get each player's money. Consequently. the bat companies decorate the bats well and employ a variety of advertising approaches, including sponsoring college baseball teams. In effect, youth baseball players subsidize college baseball. Without the youth market, there would be no contracts with colleges regarding bats.
If/when the entire baseball world switches to wood or or other solid core bats, the perceived performance difference among bats will decrease. Perhaps the bat companies will start marketing special "Brazilian cherrywood" bats or come up with some other mechanism to charge a premium, but more likely the subsidy to colleges will end up being lower.