Commercials

Why do commercials these days have to be so stupid, gross, or downright childish? Do companies no longer approve commercials before they go on the air to promote their product? Isn't the idea for a commercial, to get you to buy a product? Well not only do most of these commercials not make me want to buy the product they are trying(?) to sell, but they make me want to leave the room at best. And at worst, they make me want to throw up.