I don't like the idea of "excluding" anyone. I am not advocating a ship full of "kids" but lets face it, life is full of people of all ages, shapes, and sizes and I sometimes find" kids" behave better than adults. (I am taking for granted that the parents on these cruises are in control of thier kids and that the kids know how to act in public) I have taken my two (late teen boys) on cruises since they were each 5 years old and never have they done anything other than behave themselves. Infact, many senior citizens have complemented the boys and parents for how well behaved they are.
I have been on cruises(on the old Premier Cruises) that kids have been abandon by their parents and allowed to do anything they want. In most of those cases I found the parents"undesirable" or there own behavior suspect......Lets face it ...if the parents cut in line and are loud and rude and dont know how to respect fellow passengers....how will the kids know?
Again....I like the "mix of passengers".......thats life...thats what makes cruising interesting...meeting new people.