Well, I know this is surely a dumb question, but why didn't he find a rancher who would have let him put up the kind of fence he wanted to put up?
DUH.
At a minimum, he's trying. I don't see the Feds or anyone else down there trying to do anything.
Their border watch was very successful for being run by amateurs. But building something tends to be much more complicated, since local and county governments get involved. Cochise County did jerk them around for a couple of months, for example.
If they do not build fence this fall, I will join your criticism (unless there is clearly documented government obstruction - and I would not put it past liberal organizations to file environmental lawsuits, which IMO will be the primary obstacle to any border barrier, whether it is privately or publicly built.)
But the obstacles Simcox has faced so far are reasonable to explain.