I am truly surprised at all the compartmentalising and tarring with the same brush people here are giving teenagers. Sure, there are plenty who are selfish and spoiled and have a sense of entitlement, and I used to lump them all in the same boat too. But that's unkind and unfair. Everybody is different, and there are plenty of decent, respectful, hardworking and responsible teenagers out there. Just as there are plenty of irresponsible, selfish and spoiled adults out there, too.
IMO, if the only teenagers a person knows are spoiled brats, it may be time for that person to broaden their horizons a bit.