Because almost all of Texas is private land and to hunt you either hunt in a preserve or lease land to hunt on.....either way it is cheaper for them to pay an out of state tag and hunt here. I like them here...it keeps my hunting fees down. Imagine everyone (residents) paying $200 plus for a deer tag.
If you want to hunt elk for meat....in the back of the rifle section of the hunting brochure for each species there is a section called Ranching For Wildlife. It is a draw for residents only. It is for Colorado hunting preserves and all cow tags have to be given to residents at standard fees....it means you get a guided hunt....for the standard draw fee $45.
I get a cow tage every 2 years and fill my freezer....last year when I arrived, they offered me a 2nd tag as the DOW wanted to thin their herd but didn't hant additional hunting pressure. So I got a double hunt.