Countries have complicated trade for centuries. Free trade is a modern exception, not the historical rule.
And in principle, countries have as much right to restrict trade with Cuba as they do with Russia and Israel. It’s the same principle that allows people to call for boycotts of Amazon and Starbucks. All of these things can affect the lives of millions, in an effort to bring about political change.
Fun fact: 90% of the cells in your body are bacteria.