When my likeness is used in conjunction with a random product, there is an implicit assumption that I somehow support it. And other people may see it and distance themselves from me, refuse to do business, or refuse to hire me.

As an extreme example, how would you like it if an unscrupulous porn site featured your face on an advertisement? Even worse, suppose a prospective client or employer saw your face on an advertisement for some banned substance. In most cases, its irreparable damage.