Chick: I ask you to consider the possibility that since you derive income from this practice and we don't, we might be in a better position to look at it objectively...
When a TV commercial shows some hot bitch leaning against a Lamborghini and pouring a Pepsi down her throat while she fellates the can, they're not claiming that drinking Pepsi will score you that ass. But that's the association that the advertiser has paid a lot of money to sneak into your mind. And "sneak" is the correct word - because obviously it won't hold up to a second of scrutiny.
So yes, the supplement companies' ads don't say "Our shit can make you look like this pro". But honesty would compel you to admit that this is the message they're trying to sneak into the minds of the desperate gym rats who keep them in business. Your insistence that the pro isn't responsible if anyone is stupid enough to believe it can never change the fact that it's not, you know, nice. In fact: in other contexts, making money by exploiting people's ignorance is called "fraud".