I see both sides.
My husband is a teacher, and we have a 14-year-old son, so we are limited to cruising during school breaks. I also hate being on a ship with rowdy kids/teens and the "parents" who accompanied them onto the ship but spend little, if any, time with them afterward.
We love HAL and Celebrity, and so does our son. Like Dave's son, he is disciplined (usually), social, and polite, and knows how to act in public. He also spends most of his time with us. On the occasions he uses the kids program, we do not give permission for him to sign himself out. Sure -- he got cranky sometimes, more so when he was younger, but we would get him out of the situation quickly.
After one Caribbean cruise during February break a couple of years ago, we vowed to never cruise that area again at that time of year. It was pandemonium, with kids canonballing into the pools, kids running the corridors, and families saving rows of seats in the show lounge. (And this was on Celebrity.) After that experience, we now tend to seek out itineraries that would attract fewer families. On HAL a few summers ago, he was one of 70 kids on board a Canada/New England cruise. This past summer, we went to the Norwegian Fjords on Celebrity. Not once on these cruises did we feel out of place. Now, I can't say what people were thinking, but very often other pax would come up to us and comment on how great it was that he got to experience travel at such a young age.
My point, after being so long-winded
, is that pax who travel with kids need to be respectful of other pax -- and vice versa (so long as the "parents" are being parents).