I've had a few run ins with neighbors like this:
First - if they're out all day they probably don't know the dog is howling, and by letting them know "for the pooches well being" it may enlighten them and keep them from leaving the dog behind. I know I've gone out and left my dogs in the camper for a few hours, if they barked or howled I'd have no way of knowing it if the neighbor didn't tell me.
Secondly - there is a chance (a very good one) they don't realize how rude they're being or how loud their music is. I generally ask nicely if they'd mind turning it down a notch as I'm having trouble getting the kids to sleep/hearing my TV over their radio.
Kids are often left unsupervised, allowed to run free, and are not monitored by their parents at all when they go camping. I'm a firm believer in "it takes a village" and will reprimand anyone's kid if it's going to keep them safe, or keep my property safe.
Of course there is always the chance they're just inconsiderate and don't care, in those cases I'm glad that I'm rather intimidating and usually get immediate compliance. Sometimes though it does require a call to the campground or local authorities for a disturbance of the peace.
I don't agree with "dealing with it" or burying my head in the sand - if someone is infringing on my ability to relax, I'll address it. If more people did, there would be less irritating people in the world.
Of course I've never said there was a problem with re-routing a stinky slinky in the middle of the night and dumping a black tank under someone's camper either