The idea that all Cuban citizens are brainwashed applies also to US citizens. US citizens are also indoctrinated to believe that capitalism is the only way from when they are toddlers.
The Cuban immigrant's bias should at least be taken into account, you are selecting a group of people to interview who left Cuba because they hated the government. Of course they are going to say bad things about that same government.
"And if you ever visit the non-tourist parts of Cuba it's incredibly depressing what socialism has done to them". Socialism has done great things for the people of Cuba considering the constraints they have had put on them by the west. The government has massively increased the average Cubans literacy, improved working conditions conditions and instituted high quality free medical care making it so that wealth isn't the deciding factor on how long you live.
Cuba would be far worse in an alternative reality where Batista stayed in power.