This is a weird opinion. This kind of resale is common in markets where producers would rather guarantee selling their entire product at a certain price as opposed to risking overpricing. Same reason many farmers sell off crops immediately to middlemen instead of trying to maximize price selling directly. They aren't being exploited, they're hedging risk. I would imagine that centralized ticket websites like StubHub also improve the venue's distribution in this case. If venues don't like resellers, they can follow Louis CK's actions[1].
[1] http://thenextweb.com/media/2012/07/03/louis-c-k-sees-ticket...