The Antifa attackers dont like free market and capitalism. They are communists and Marxists. They want to shut down the voices in favor of free market using violence.
Antifa is not ignorant. They are much more dangerous than that. They have a point of view and a desired outcome - the desired outcome is turn USA into Cuba or Venezuela.
Don't get how the Free Speech Movement applies to that. They don't specificly advocate those things do they?