Why is there only ONE Anytime Fitness in the entire city of Houston?

I find this odd. In this entire city, there is only one anytime fitness, but countless other 24 hour gyms. Is it not possible to run an AF in Houston? There are a butt load in the surrounding suburbs.

Is there a zoning law or something limiting them? I've been to other states that have plenty and they seem to be popular, so I can't imagine it's a demand issue, especially with how busy the Yale one gets. What gives?