Some more thoughts....
Stubhub is obviously making money off this quasi-scam as they get to charge fees for all the scalped tickets, so they are in favor of seeing this continue.
The venue (or whoever is responsible for putting on the show) likes this situation as well since it ensures they sell out every show, for if the show wasn't to sell out, their would be supply available and the scalpers wouldn't have the pricing power to jack their prices up unless they got all the good seats or something like that. So the scalpers have to buy up all the remaining tickets in order for their scam to work.
The scalpers then have amasses large inventories of tickets that may or may not sell. I assume they don't sell a fair fraction of their tickets, so they have to make it up off the tickets they do sell, hence the huge gouge in pricing. The whole scheme is very anti-fan.
I went to see some shows that were "sold-out" at MSG, including Arcade Fire, Muse and Iron Maiden. Sure was a lot of empty seats around me for shows that are supposedly sold out.