I would point out that it is perfectly possible to be a worse predictor than a random or max-ent predictor; if all economics does is - per the quote - remove our (Marxist/Communist/socialist/Keynesian/mercantilist/Maoist/Catholic/...) delusions that we can improve on the normal workings of the economy, it will have done us a useful service indeed. Aside from the very simplest predictions relating to supply-and-demand, obviously.