From my point of view, high speed rail in Texas’ point is not to reduce traffic in the cities themselves but to reduce traffic on the limited highways between cities. And at night, it could be used to ship light freight and mail between Texas cities, a task currently done by tractor trailers.
Also, Texas is union-hostile.
As an example, I travel 12-13 times per year in order to attend athletic events that may take from 2-4 days. Now with equipment/baggage/nutrition/fluids/computer/and "stuff"... it would be a pain in the neck to load it on a train after taking it to the station. Then load it all back onto a car/truck and then go to the events. It's just more convenient to throw it all in the back of my crew cab truck and go.
Same for hunting trips and trips to South Padre/Corpus Christi/San Antonio. ..... convenience. Now the mail/freight/other deliveries... sure why not rail. But nothing beats the convenience of leaving when I want and just going. Freedom. I'm on my own schedule. Same with busses. I try to get to work 20 minutes early and I don't want to be crammed next to some strangers on my way in that may mug me or just get in my bubble.
That's why I hated living up north. It was a Pain in the a##. I NEVER will live north of the Red River, east of the Sabine, west of the Pecos and south of the Rio Grande. I've been packed in like a sardine in several cities in the northeast, florida, and california. I've found right where I need to be and it isn't in a place that I HAVE to be packed in a wheeled or railed box with strangers everyday.