One of the big hurdles for the Texas State RR is it was never intended to make money. It was developed as a Texas State Park utilizing an existing State-owned railroad, that unfortunately is not in a high tourist area. It's funding came from the State Parks Dept., not from revenue generated from ticket sales.
It is interesting to note that both Texas State RR and what became known as the Grapevine Historic RR (formerly the Tarantula Train) were both the brainchild of the same guy, Ed McLaughlin. The Tarantula Train was funded by a Ft. Worth oil man who wanted to create a legacy for himself in his beloved Ft. Worth. So, it was never intended to make money either.