When the Iranian people rose up against their oppressors early in Barack Obama's presidency, Obama neither said nor did anything to show support for them. Why? Because he didn't want to piss off the mad mullahs, with whom he fully intended to negotiate the nuclear deal that stands as one of the worst agreements an American president ever made.
I would say another reason is that Obama genuinely had no sympathy for the Iranian people. When he sees oppressive regimes around the world, he thinks to himself, "America is no better," so it's not a priority for him to advocate for the freedom of people like the would-be Green Revolutionaries who got brutally put down by the Iranian regime.