Let's look at an "evil government" index to determine the "evilness" of Cuba among authoritarian regimes. A good one is the Democracy Index put out by the Conservative economics journal "The Economist".
Cuba ranks at 124, which puts it in the top 20% of authoritarian regimes, so 80% of them are "more evil". We certainly don't do any business with those 80% do we? Near the bottom of that list is our old friend Saudi Arabia, a regime we absolutely should not support right? Others in the "evil 80%" are Nigeria, Kuwait, Afghanistan, Tunisia, China, Qatar, Oman, Vietnam, and the UAE. No way we do we have diplomatic relations, do any business, or offer any support to any of those guys!
Of course six of these Evil Nations have oil, which makes everything good, correct? Well, it turns out that Cuba has useful offshore oil as well, so geology automatically promotes them to Tolerable Oil Nation, even if their much higher democracy ranking does not.