If the scalpers didn't exist, the eventual ticket-holders would still be able to purchase from the original vendor. It's not like scalpers make tickets magically appear.
A lot of them wouldn't, though. If the scalpers sell the tickets for, say, $500, then the people willing to pay $500 get tickets pretty reliably. If the scalpers didn't exist, those people would have to take a roll of the dice along with the many, many more people who are willing to pay $45. A lot of them wouldn't be able to see the show.
Really, my point is more that those tickets were going to sell anyway, and all the scalpers are doing is reducing the potential audience for those tickets. I don't see how this specific market is 'smoothed' by this practise.