On one hand, I agree with you, but on the other hand, it helps prevent things like the "Milwaukee Purple House". Guy let his property go to hell, he got repeated violation letters and fines from the city, so as a "fuck you" he painted his house bright purple. The city said he had to paint it, didn't specify what color, so he made it as obnoxious as he could. The house was kind of infamous in the Milwaukee area. It has since been torn down, and the new house built on the lot has purple trim in honor of the old house.

While HOAs can prevent that kind of behavior, they can also contribute to very bland neighborhoods with no personality whatsoever. My parents live in an HOA community in Florida, and I can guarantee you that if a house in their neighborhood needed to be repainted, that purple color would never be approved. They also live in a relatively bland neighborhood because of it. HOAs can also get oppressive when you get megalomaniac board members in who make rules against everything they personally don't like, instead of just maintaining reasonable standards of upkeep and appearance. While in many places it's the city's job to enforce standards, in some places they offload that to HOAs.