The lie of capitalism is that society won't result in one group living at the expense of others: just let individual pursuit of maximization of marginal value run, and it'll all be good.

It's not all good. There are many ways in which one group can live at the expense of another, even if all you get to do is make reciprocal trades of value.

The lie of corporatism is, I agree, that, well, "too bad". That's just how things are: one group lives at the expense of another.