Apparently, Ticketmaster's business model is based on taking the negative public relations hit for charging higher prices on behalf of their customers.
If you create a startup called CheaperTickets.com with the noble intention of not charging those hated service fees, you won't get any customers. (Keep in mind it's the venues & the artists that are the real customers of Ticketmaster and not the ticket buyers). The venues want the lucrative cut of the service fees while Ticketmaster gladly takes the heat.
[1]http://www.laweekly.com/music/ticketmaster-and-servants-band...
[2]http://www.reddit.com/r/todayilearned/comments/1xlt0i/til_ti...
Pearl Jam tried to stand up to Ticketmaster with a boycott and lost.
Unfortunately, Ticketmaster has a habit of just buying/merging with competitors (including Live Nation, in a merger that should have never been allowed to go through).
Plus, Live Nation actually owns a lot of venues, so you'll never see them use another ticketing provider: https://en.wikipedia.org/wiki/Live_Nation_Entertainment#Venu...
Ticketmaster is practically a saint next to them in my eyes.
Ticketmaster owns a Stubhub competitor. https://en.wikipedia.org/wiki/TicketsNow
Now individual/corporate ticket brokers are for sure buying up bulk tickets and putting them on the secondary market through StubHub... but StubHub doesn't have anything to do with that besides being the platform utilized.
The barriers are the very typical ones that big companies (as a matter of fact, I assume that the venue with the greatest exposure are in fact big companies) face towards innovation: bureaucracy, lock-in, inertia, PHBs, and so on.
Not that TM doesn't have any positive side - it's just a very typical example of the business workings of large companies (not all, of course).