I see two sides to this. I don't have a problem with people decorating for Halloween, but if I lived in a tight lot / typical neighborhood and the guy right next to me ran a haunt attracting a line of 50-100 rambunctious kids at a time, that might bother me a bit.
As a general rule, though, I'm mixed on HOA's. They might help keep someone from putting a junker car in a driveway, or letting their lawn turn into a jungle, but at the same time, they also restrict someone even having a nice boat in their driveway. They're a real mixed bag in terms of benefit and just plain nuisance.