Being TOLD to turn it off? I probably wouldn't have acknowledged the guy. Respectfully being asked to turn it off? I would have weighed the pros and cons. Why did I have it on in the first place? Was it on to give my camper AC so my kids could sleep? Was it on just cause I could?
If I was planning on leaving anyways, I would have been turning it off anyways.
Generally I try not to be a jerk. My dad taught me to be aware of people around me and not act as if I'm the only person in the world. I prefer camping with electricity, so I camp at places that offer electricity. In 13 years of camping, haven't needed a generator yet...