While I get what you are saying, individual responsibility only gets us so far. We need societal-level change, and holding corporations accountable isn’t just about reigning in their direct pollution. Corporations control what choices that we as consumers even have, and regulating then so that we can only pick from a variety of good choices – or at least so that the bad choices are more expensive / effort – is much much easier than focusing on getting individuals to make good choices when bad choices are easily available, cheaper, and easier.