Exactly! This example of private contract law is really the right way. To be fair, Houston really developed post-car + cheap land which explains the low density.
What's the advantage of it? It's just a municipal government by another name, but with fewer safeguards, and a throwback "votes only for landowners" style of voting. I'd personally prefer to be regulated by a proper local government than the strange quasi-governmental abomination of an HOA.
Had this been the norm last century, Palo Alto would've been developed with these kinds of restrictions, and instead of the Palo Alto city government with its NIMBYism, you'd just have the Palo Alto HOA doing the same thing. You actually see that in one part of SF currently: the least dense neighborhood in SF, Forest Hill, is the least dense in part because it was developed by one of the country's early HOAs, the Forest Hill Association, which works hard to keep it suburban and "small-town".
When conditions change, and the community would be better served if some of those restrictions were changed, is it easier to change municipal zoning codes, or to change individual contracts and deed restrictions?
From what I've seen, it's nearly impossible to change deed restrictions; even restrictions like "you can't sell to african-americans" stay on the books, but just become unenforceable. At least with zoning laws, it's possible (if hard) to de-clutter them.
