A better question is, why is ticket scalping not illegal in every state? These parasites take unfair advantage of the majority of people who have real lives and can't get to box offices very early to beat those who grab quantities of tickets for major attractions. Then they sell them at hyper-inflated prices.
None of that bloat goes to the performers, whose shows are the actual item of value, or to the venues, who have to cover their costs and make a reasonable profit to stay in business. All it does is put a huge layer of expense between those who earn the money with the shows and their audiences. If they charge more than one or two percent above the face price of a ticket, the only difference between so-called "legal" scalpers (TicketMaster, etc.) and the phone banks and street hustlers is that the licensed ones are paying graft to officials in the locales they rape.
I think all scalpers should all be jailed and forced to pay a continuing fine of over fifty times the costs of their incarceration to cover the cost of their prosecution and interment. :|