I think you are vastly underestimating the horrors of most pre-revolutionary societies, and probably also overestimating what you describe as oppression in post-revoltionary governments.
The third, and perhaps most disastrous of our failures, was the decision to give stature and support to one of the most bloody and repressive dictatorships in the long history of Latin American repression. Fulgencio Batista murdered 20,000 Cubans in seven years - a greater proportion of the Cuban population than the proportion of Americans who died in both World Wars, and he turned Democratic Cuba into a complete police state - destroying every individual liberty.
And JFK was no friend of Castro; he greenlit the Bay of Pigs invasion! Revolutions are born from the most brutal forms of exploitation and violence. Not even the wildest anticommunist propaganda about post-revolution Cuba comes close to the reality of what the revolution replaced.