I dont think its somethng that the Castros can bring about, but only cause to end if they bring changes that will negatively effect too many people. Although we see that living standards (meaning both physical and mental) as being far too low for what we’d accept, a whole lot of people in Cuba who although not particularly happy with their lot, don’t see things as bad as we do. Sometimes this will be because they don’t weigh things like we do; other cases they lack the possibility to compare and decide.
As mentioned many are concerned about changes that US or Miami Cuban involvement might bring and balance what they know against an unknown which may bring them a better life or a worse life… Remember the Cuban government makes sure they know what life was like for many under Batista, and how the US contributed to that and how most of teh people responsible took off to Florida in 1956 plus.
Mind you I’m not saying things are peachy now - far from it.
Anyway, thats teh view from here.