It is, indeed, a cynical statement. But it gets to the very reason why we aren't looking closely enough at the potential social costs.

As an aside, I think the conventional wisdom reading of Adam Smith, that somehow selfishness begets virtue, was not the author's intent, and is mostly just a self-serving rationalization. At the very least, it ignores the ways that selfish action can turn toxic - deception, corruption, theft, and of course externalized costs.