a |PiX!e |)uSt ----- Unfortunately, that is always the case ... a few bad ones in the crowd give the whole group a bad rep. My DH taught hs for 16 years and there are a lot of very nice young people. However, keep in mind, when you are in big groups and a little loud, it may not seem bad to you but others who are not around teenagers consider the loudness to be inappropriate. And, there are times when language can become an issue especially for those with young kids. All too often, it is a matter of perspective. And,it also depends on the kids.
That being said, on my vacation, I prefer to enjoy it in a much quieter setting than that enjoyed by teenagers. And, we too, go the other direction when we see large groups of teens, especially at the parks. But you are right, there are many out there that are very nice and responsible.