Economists have studied that question a lot, and the general result is that the theoretical models work quite well, even on substantially imperfect markets. I

Economists have studied that question a lot, and the general result is that the theoretical models work quite well, even on substantially imperfect markets. I think these concerns are pretty similar to the religious idea that "evolution is just a theory". Our human minds really don't want to admit any facts that would force us to change our world view.