While this may be true, you seem to be ignoring the prisoner's dilemma part of this... yes, society (and the individuals in it) will be better off if everyone cooperates, but as an individual, it is still always better to defect.

Imagine, for example, there are two companies that make widget foo. They are identical, except Company A charges less than Company B, but Company A pollutes a bunch.

As a society, we want everyone to buy from company B. We would all be better off.

However, that isn't my choice as a consumer. I either buy from B and pay more, and company A still pollutes (one person out of thousands doesn't change the amount of pollution).

Or, I get the cheaper thing from company A, and everything else stays the same.

Why wouldn't I shop at company A? My one purchase wont make or break the company, and it won't change the amount of pollution by any noticeable amount... but I will notice the cheaper price.

This is what a collective action problem is.