Answer by Margaret Weiss:
It is an issue of morality, so just like other topics you had listed, it goes to the heart of what barriers would movie makers cross to get to the audience; will the age stop them?
A more elaborate response is within this link:
Let me quote one reference:
“Advertising at its best is making people feel that without their product, you’re a loser. Kids are very sensitive to that.”
– Nancy Shalek (former president Grey Advertising)