The rules should exclude advertising to prevent from this kind of visual pollution. There's more than 382000 pictures on this web site, so we don't need pictures containing ads. If you don't agree, maybe you're in trouble with your dopamine (it's called an addiction).
Many of the girls only post on instagram and stuff because they have sponsorship. I would hate to discourage them from posting by making it less lucrative for them.
If by ad you mean their Instagram or twitter handle I have no problem. There are people who are posting pics without adding a name to them, and this is the only way to find out who these girls are.