[mh-]

you're free to do that now: outbid them, with your money, for all of the advertising spots.

then you can promote whatever you want - until someone else comes along and decides to obstruct you, of course.

[unalone]

That's facetious and doesn't address OP's point, which is that certain industries are banned from advertising their products in certain ways when said products could harm their users.

I don't agree that Facebook is necessarily at the point where we can call it harmful, but your "all you need to do is outbid Facebook" spiel is some smarmy nonsense – not least of which because Facebook itself owns some premier adspace outright, which it's more than willing to use to spam whatever new product of theirs that they'd like.