Why can't he, or I, diminishing the legitimacy of economics?

If someone had made up a fake Nobel prize in psychology I would diminishing the legitimacy of that too.

The field of economics is far, far less rigorous than any of the hard sciences for which Nobel prizes are awarded. The fake Nobel prize for economics is strongly disputed by much of the Nobel family, Keynes, and it makes economists act more blowhard, self-congratulatory and self-important than they already do.

I say this as someone spends a fair chunk of my time reading economics books and blogs.