If a home buyer flips a property, he or she is considered a smart investor. Similarly, a scalper invests capital in buying tickets, and this capital has been at risk. For this he earns a return. What's wrong with that?
If an investigation into scalping is in order, why not investigate the owners of the sports teams, who actively collude to restrict the number of teams, the number of games played and the TV broadcasts? In effect, they scalp the public with high ticket prices. Go after the artists who restrict the number of performances and the sizes of their venues to scalp concertgoers. Investigators could even look into gas station owners, who after the refinery fire in Northern California have "scalped" their in-the-ground gasoline inventory.
If you think any of these crackdowns would be ridiculous, then it is just as ridiculous to go after ticket sellers.