I have no problem with you or anyone preferring other lines. I just object to any kind of generalized negative comments about anything, be it cruise lines or people. And, while I have sailed on many different lines, I have rarely seen any difference in overall behavior. I was on one Carnival cruise that did seem to be a low class crowd, but most of the time, there is little, if any, difference. Average age on Carnival is now somewhere around 45.
Back when they were uber-cheap, they did attract a younger crowd and it was a LOT rowdier. In fact, I refused to sail on them for a long time. But, now they are totally mainstream. And, I have to question generalized negatives if the person hasn't been on a given cruise line recently.
The worst cruise I have ever been on, hands down, was on Princess. So bad that my hubby refuses to go on them again. And, I agree with him. But, at least I recognize that it was just one cruise and hence does not necessarily represent all Princess cruises.