Rail only going to a fewe small city's would be underutilized. Ballpark 1/3 of the people going from A to B using high speed rail and you need a lot of people going from A to B. However, if B is on the way to C and people from A and B also go to C... etc you start to see massive network effects.

Sure, if Texas wants to spemd their money go for it, but this would be a relative ware of federal funds.