From the horse’s mouth.
Emanuel Derman, Economics Professor at Columbia University:

“My gripe with economists is not that their models don’t work well – they don’t, look at the role of central banks in the financial crisis – but that they seem so reluctant to acknowledge the riskiness of their advice… As a result their public arguments have an incestuous yet masturbatory quality that is exhausting to follow. The only field more self-confidently but just as regularly wrong as economics is nutrition, whose recommendations to shun butter/margarine or red meat/carbohydrates regularly reverse themselves. Natural scientists […] at least can more or less agree about truth and efficacy. Economists cannot, except by using statistical regressions which are often flawed and prove little.”

See here more economists sincere quotes on economics. Be ready to be surprised – actually, not so much 😉