I don't think the amount of damage is as great as the landowners claim. I live in TX and I hear farmers/ranchers complain about hogs all the time. When I offer to come shoot them they say sure for a $150 a day fee. I tell them to keep the pigs. If they truly had that much damage they would welcome hunters and not worry about a trespass fee.

Many landowners cry about the hogs but treat them as a source of income from hunters. Due to that they don't really want them shot out. Note this doesn't describe every landowner, but it does describe an awful lot of them. Since there is no closed season on hogs they sell hunts all year long.