There was not actually deregulation. The markets were still highly regulated, so the act of deregulating part of them threw the whole system out of whack and everyone wanted to reinstate regulation.
Libertarianism is like prayer. If it works, the religion is right. If it doesn't, you did something wrong and it's right.
Examples abound. I just mentioned one deregulation example because such things are often touted as libertarian accomplishments when in fact markets are often still highly regulated and the deregulation was just a handout to one interest or another.