Part of the problem is that while Houston is more "livable" by the metrics you quote, it is much less so by other measures. The climate isn't good. The gulf coast isn't appealing the same way the cali coast is. If you really are in the "global elite", you can choose to live a ton of places with more natural beauty, better climate, more significant cultural and art events, etc. - basically by definition. So why wouldn't you?

I like the city, lots of good stuff there. It has essentially nothing bounding growth, and that helps keep real estate and rent down I suspect.

The "elites" like demonstrating that fact by collecting scarcity. There really isn't much to be had in Houston from a real estate point of view; there isn't even much in the way of fancy neighborhoods. I mean, they exist but they aren't anything special. Partially perhaps because the whole area is pretty homogeneous, there isn't a part of it that is clearly advantageous in the same way, say, NYC, SF, LA, Chicago has. I suspect this is self fulfilling .