Eh, I live in Berkeley, a lot of the neighborhoods here are amazing, and there are almost no HOAs (besides the kind that keep condo buildings running). It's nicer than the bast majority of American suburbs I've seen. If anything, the amazing yards and cozy houses are only viable because there is no HOA pushing down arbitrary top-down rules on aesthetics. Forcing people to have traditional lawns would have totally killed the place.
You forgot one important detail, the average price of homes in Berkeley. Anybody spending $1M on a 2/1 craftsman bungalow is going to also drop a few extra dollars on landscaping.
Berkeley is indeed a great example of how nice areas can be when the evil of HOAs is not present. I greatly enjoy walking the neighborhood streets of Berkeley whenever I'm there.