The question is are they good reasons. It's probably a mistake to assume that our current knowledge and understanding of economics represents progress from where we were before.

Having just finished a detailed account of the history of economic thought I can assure you that there were times when economists far better understood the nature of prices that came well before Adam Smith and Ricardo-both of whom didn't really understand prices at all.

Schools of thought tend to continue until they reach a dead-end that's impossible to ignore. A new school picks up the pieces and continues on again. We have seen that with the fall and rise of Keynesian economics.