> Where does this romantic idea of poor but free but noble peasants come from?
It comes from people promoting socialism and communism. They need to lie to justify an oppressive system that only develops through force. That's way you have talk of communist and socialist revolutions - they don't happen on their own because they require the creation of massive bureaucracies that have a monopoly on the use of violence.
No one ever talks about a "capitalist revolution", because capitalism evolves organically, as free men and women voluntarily trade goods and services.
Sure capitalism has plenty of issues, but thus far it's the least worst system out there.