Well, that's not strictly true.

By raising the price of tickets to what the market will bear, they force some people out of the marketplace, increasing availability of tickets for those who can afford them.

And from the perspective of the artist and Ticketmaster, they eliminate some of the risk of tickets going unsold.

Of course, it's understandably seen as very unfair (goodness knows I've missed out on shows I wanted to go to because scalpers raised the price beyond the level I was willing to pay), but I wouldn't say it has no value.