Perhaps if the left had won the civil war, they'd have been as bad as Franco, and perhaps not. Who knows? But as it is, it's the Spanish fascists and their Catholic supporters who got the victory at the time - and the responsibility for the dictatorship in the minds of people now. No doubt people's recollection of the Civil War is coloured by what came after - with the left getting more sympathy now than it deserved at the time, simply because they were the losers and they were oppressed afterwards. It will take a long time before Spain can look at that civil war dispassionately and objectively, I would imagine.

As for your general comment, I'm rather confused by certain inclusions (Cuba, most notably), and you can't exactly call Cambodia long-lived (you have to wonder if anyone would've survived if it had been long-lived...). But to stick with the less dubious examples, Italy and Spain vs. the Soviet Union and China, it's true that the latter two had some spectacular economic failures that added starvation and economic deprivation to the totalitarianism and oppression of dissenters that happened in all four countries. Though if we're going to compare, one has to mention the - admittedly short - list of positive points of communism as well, most notably its respect for minorities and their cultures. And of course in Spain's case the oppression of minorities, making it illegal for them to even speak their own language in public, is one of the things Franco's regime was most notorious for. Considering how dedicated to Italy and Italian culture you are, I'm sure you can appreciate how awful it would be if you lived in a country where you could be fined or thrown in jail for nothing more than speaking Italian in public.