Ticketmaster doesn't actually want to stop scalpers, they only want to pretend they do for the Hot-ticket big name acts. Scalpers are a customer of Ticketmaster, they are paying full price for the tickets and for every Springsteen on Broadway ticket that sells out in seconds and commands big money, there are about a dozen medium/smaller acts that scalpers get stuck with tickets that were not going to be sold.
I'd imagine ticketmaster's revenue would drop by a not so insignificant margin if scalpers were taken out of the game.