How Cuba is a succesful system?
I don't think it a matter of taste, I think your definition of succesful is problematic.
Success is subjective. I'm not a fan of top-down socialism, so I wouldn't choose to live in that kind of society. But the Cuban socialist system did succeed as defined by Castro's objectives, the healthcare system has a good reputation for treating patients well, despite a lack of resources or new technology to do so. Their stock of automobiles is impressive for similar reasons.
So Stalin was succesful because he took control of half the Europe, Hitler was succesful because he killed a lot of Jews, and Pol Pot was succesful because he killed a lot of intellectuals. Don't be so restrictive with your praise, all dictators are cool and succesful in their way.
Successful genocidal maniacs, yes. I won't praise that sort of behaviour though, because it's heinously immoral.
Even Castro or Chavez were/are somewhat immoral in my eyes, as the population were given little choice in how they lived their lives. Moral values are not universal.
It's not because something isn't universal that the relativism should prevail. Even if values are not universal we still can make a hierarchy between different values.
Incest, excision and cannabalism are a cultural reality in some tribes even nowadays. We can judge this kind of pratices as inferior regarding the criterion of the potential to build an advanced civilization.
Yes. I concede that moral values are rooted in the self-preservation/self-improvement instinct in social animals, and that some moral values are universal. Would you concede that Chavez or Castro largely observed basic morality in respect of their own citizenry?
Killing their own citizens, putting them in jail and to have imposed on their country an economic system which keeps the citizens poor doesn't fit into what I would define as basic morality.
I would concede they are not mass murderer though.
And it's not because some people think communist is cool and help the human race to move forward that we cannot say that they are utterly wrong and forget the empirical data that shows that the communism do the exact opposite of its intended goals.
Except in Cuba and Venezuela! It might not have been the promised idyll, but they were dealt some difficult hands by the international community also.
At the end of the day, Stalin and Mao were unapologetically evil tyrants, they would sacrifice any number of their subjects' lives in order to preserve "the system" (which was really just a euphemism for their continued unchallenged rule). Chavez and Castro, for any and all their faults, were no
murderers mass slaughterers. (they likely did murder on a small scale, I don't know the details well enough)
I can understand your perspective on socialism and communism if you are a French citizen (thankfully you are not a subject of the state, yet). It looks from the outside as if France has long ago "run out of other peoples money", as I believe to be the classic Margaret Thatcher socialism quote.
When communism failed (that is, every time he has been tried) it's never the fault of the communism, it's alway due to the other countries which are not communist. Ludwig von Mises has written something about that in
.
For instance, Allende supporters think the economic meltdown of the Chile was due to the action of the evil CIA whereas anyone who knows the real story understand that he deliberatly introduce suicidal reforms in the sole purpose to ruin his country.
Of course socialists (yes as a French I know them well, basically every body here is socialist with only differences in degree) thinks that if Chavez and Castro have failed to produce other things than poor people it's only because of the evil action of the non-communist countries. That belief prevents them to think about the question further and allows them to preserve their shitty belief system about how the economy works.
I think all governments are guilty of those crimes, though. 
