You make it sound so trivial and whimsical.

Populist means the people have the power to control the government and not the other way around. It means that the the government works in the best interests of the entire population and not just the monied and well connected elite. It means that government is not just a tool for the elite to keep the little people in their places.

Considering that most slaves throughout history could buy their freedom, many could own slaves and engage in commerce, it could easily be argued that we are all slaves under the current system. That would be the opposite of a populist government.