In the US, you can go anywhere you like in the wilderness because it is not owned by anybody, or at the very least is public land, i.e. you have access to walk/camp as you see fit. Correct?
In Britain, we have no wilderness because it is so small (about the size of the state of Oregon), and every bit of land is owned by somebody. The larger areas of open ground, moorland, heathland, lakes and mountains, are all owned by somebody. It used to be at their jurisdiction whether you could walk through it. The Right To Roam gave ramblers the right to enter private land on certain specified footpaths, as long as they didn’t set up camp. Ultimately this is a good law. These areas of land, although owned by somebody, are usually in the back of beyond. It’s not as if you’re walking through their house.
And who gets to make that determination? If you allow them on your property and someone is hurt, who are they going to sue? If you allow them on your property, what's to stop them from coming right up to the house, or even inside if you're not home?
It seems to me that I've read some articles from Britain where someone has left their home to have it renovated or remodeled, or even just for a short three or four day trip, and have come back to find squatters living inside the house.
Private property is private property. No one has a right to be on my property unless I say so ... and the good thing about Texas is that, after dark, I can defend my property with lethal force if need be.