They were simply siding with their Russian comrades who to this day prop up all these communist and other US-hostile regimes.
Looks like you didn't look close enough at their signs and placards. In all but one instance (Iran) they were pushing the pro-communist Russia agenda.
Regarding Venezuela, they (Code Pink) were supporting the Russia-backed Maduro (Hugo Chavez) Marxist regime. In Iran, the Russia and ChiCom-backed regime there. In communist Cuba, the Castro regime. In North Korea, they're calling for "reunification". In other words, one Korean nation under a Russia-backed communist regime.