It's really just market making. If the venue sells the tickets for much less than people are willing to pay it's very reasonable that people will buy them to resell them. Want to stop resale? Price the tickets closer to the real value.
But anyway, take it from me, music fans are irrational types who won't see it that way. I've encountered significant resistance at my suggestion of dealing with the scalping problem. An idea exists that the 'real fans' should be able to get tickets at a price they can afford, for whatever definition of 'real' means that the person speaking falls into it.
Plus, sometimes tickets can be sold at market cost, but by taking advantage of the upper end of the market and by limiting supply, scalpers can still be profitable even when only selling a small proportion of the tickets they purchased.