Do you think this is valid for todays HOAs in general? Seems like a weird point to make today. I doubt the main purpose of a Home Owners Association today is keep out unwanted ethnicities.

Yes. They're often used as a form of legal economic and cultural discrimination, instead of simply to uphold quality of life in the neighborhood.

How?

Rules that prescribe particular materials or levels or methods of upkeep that are significantly more expensive to implement or maintain than others, or that clash with one's culturally-based desires. A common one is a prohibition against small farm animals or front food gardens. Another is part of a hustle where a required exterior finish is only available from a privileged provider or contractor, similar to how apartment buildings limit your choice of ISP.

Failing to adhere to HOA rules (which may not be readily apparent) results in fines and conflict with a group that's empowered to make decisions about your property. When homeowners have these decisions taken away and are forced to shell out, it becomes a financial and psychological strain that prompts people who would otherwise be enjoying the property to leave (or to not purchase it in the first place).

I repeat this idea to others all the time. Anyone that doesn’t believe it must not have experienced much or any racism at all.

I live in a condo in the suburbs of NH. My neighborhood mostly looks like a series of houses smushed together like townhouses in a city, but with a shared spacious yard in front of them & behind them. Most of them are linked on both sides but there are also ones that are only linked in pairs. It's certainly an efficient use of land and I ended up with something much nicer than if I had bought a traditional house.

My neighborhood has an HOA. I'm not allowed to use a grill on my deck. I can't just leave piles of trash in my yard. I can't install a garbage disposal unit in my sink. There are rules and the kind I would have really rolled my eyes at when I was younger.

But these rules, the HOA, they are required by state and federal law: https://www.hopb.co/new-hampshire

Condos are "common interest living spaces", if someone's house caught fire it can spread to the others. If the septic tank gets screwed up we all need to contribute to get that fixed. There are certain liabilities involved here that require some kind of legal entity to adjudicate, this is the role our HOA fills.

While I don't have the numbers, I speculate that the majority of HOAs in the United States were likely created for similar reasons. Fundamentally an HOA is kind of like the residential version of a workers cooperative, they enable high density housing where everyone gets to have equity. Living under an HOA will always be better than living under a landlord, yet I feel few make this connection, especially when considering who is more likely to discriminate.