Or it's a condominium development and you need a HOA to deal with the roof and other shared maintenance issues, and things get tacked on.
It is painfully easy to avoid a HOA if you don't want one, but once they exist they stick with the house for basically forever.
And the underlying aspect remains, which is keep poor people out (often explicitly racist, mind you): https://www.nbcnews.com/news/latino/ugly-legacy-latino-coupl...
Even though not enforceable, they often remain and people still sign them. https://www.vice.com/en/article/y3ppgw/californians-can-now-...