Negative externalities are a big downside of the way we structure capitalism, but identifying cases where it hasn't been penalized by the market (e.g. by making a deadly but addictive product) is not an argument against a case where it's reasonably postulated that the market will react appropriate (e.g. your product is not safe in an industry where everyone prizes safety highly).

That just screams, "I don't understand the economics of capitalism!"