the Ba'ath was never a grassroots people's movement that sought to mobilize the proletariat for revolution, they were clandestine bourgeoisie that achieved power through the military and in Iraq's case, with the aid of the CIA. when Salah Jadid tried to implement authentic socialist reforms, he got thrown in the bushes with the quickness.
the communist party was popular throughout the region, particularly in Iraq and Sudan.
people didn't see the Arab "spring" on the horizon either.
Just b/c Saddam was a U.S. puppet didn't mean Nasser and other folks were with that. They were all for Arab Nationalism.