JoeMal, we have nearly 25 million people in Texas. Roughly 7 million of those are under the age of 18. Of the remaining 18 million, less than half are land owners and of those that are, something like 90+% only one a residence or residence property and do not own property that is or could be suitable for hunting.
In other words, there are lots of people with no land that would like to hunt for free, millions of them. We don't have a shortage of that type of hunter. Flintknapper mentioned a few issues, but really only scratched the surface of the trouble that such unencumbered hunters can cause.
Are hogs a problem? Sure, but as noted, they are a commodity. How much of a problem are they? Well depending on estimates, there are 2-3 million hogs in Texas. They cost Texas roughly $60 million a year in damages and abaitment efforts. So on average, each hog costs us $20-30 per year, or roughly $1.65-2.50 a month. So hogs do cause damage and cause expenses, but how much money are you really going to save me by coming on my property and shooting a couple of hogs? How much risk will I endure from you for being there? Having you there for free may end up costing me a lot more in the long run than having a whole mess of hogs. The biggest risk that I can't get away from is that since I don't have any legal agreements with my neighbors about having hunters come on our properties to take hogs mutually, what happens if you shoot at an animal on my property and the bullet leaves my property and strikes my neighbor or one of his prized bulls? What is going to keep him from suing me for your incompetent actions?
In a lot of ways, hogs are like mice. They tend to damage by sheer numbers and not by the singular actions of individuals.
Let me put it another way. Let's say you need somebody to stay in your house while you are away for a period of time on vacation. Are you going to let a stranger stay in your house? Sure, they would help with your problem of having somebody stay there, right? However, are you going to trust them to do everything right in your home and not end up causing you more problems or causing you to suffer more expenses than if you didn't let them stay there?