People's homes are usually thier largest investment. I don't think it too odd that they want to make money on the deal by entering into voluntary agreements to maintain certain standards.
This goes doubly for those who have to move, every once in a while, due to employment. Nobody wants to take a bath on their home investment because Cletus guts his deer in the front lawn of his home in suburbia & leaves the viscera to rot.
I think of HOA-whiners as the flip side of the rural-newbie whiners. You know, the folks who snivel because they smell cow flops when the wind blows off a neihboring cattle farm or when Cletus guts his deer in the front of his rural property. Both want others to accomodate their wants & needs, without regard to locally settled parctices and agreements.