The truth is Cuban citizens and their families enjoy a number of privileges that the events and outcomes from the Cold War era blessed them with. So of course, they vote for continuity. To put things bluntly, they get their health and education benefits to this day so they think for everything else and everyone else in true anti-colonial fashion. They unsurprisingly went full anti-imperialist after Kennedy attempted to oust Castro. As we can see, they threatened the Soviets and there is no need to even imagine if the crisis hadn't ended.