The USA has a long history of making friends with despicable regimes. As more despicable than Cuba, I'd put: Myanmar, Afghanistan, Uzbekistan, Pakistan, Azerbaijan, Saudi Arabia, Tajikistan, Rwanda, and Cambodia. Arguably tied with Cuba would be: Honduras, Qatar, Bahrain, UAE, Kyrgyzstan, Kenya, and Uganda.
Then, if you travel back in time, you have despicable regimes in Iran, Chile, and Argentina.
Trade is ultimately for more powerful in making positive changes in these societies.
My guess is that you come from the wingnut wing of the American political spectrum, and thus have a "four-legs-good, Cuba-bad" mentality.