From your artice:
"MythBusters looked into it and found that the ball comes off a corked bat markedly slower, and concluded that the cheaters have only been cheating themselves."
It’s not about the speed of the ball coming off the bat. It’s about the greater bat speed that is generated by swinging a lighter bat. A corked bat doesn’t help home run hitters, but it is a great advantage to a contact hitter like Pete Rose.