I think often the people these ads are aimed at is those who are looking to buy themselves the cars. It may well be that some 16yr brat gets a new lexus convertible but I don't think that is as prevalent.
I don't understand it making people feel like shit either. Perhaps I am just biased because of my vehicular tastes, and someone trying to woo me with a stock lexus IS350 or BMW 3 series may as well stand on a hill and piss in the wind.