The Revolution was not marxist until 1961, two years after Castro came into power, and after the USA began being openly hostile to it.
People there were literally dying of hunger, the redistribution of land succeeded in feeding them.
But of course seizing the land owned by a corporation is a violation of Human Rights, whereas underpaying workers to the point they die of starvation is just business. /s
That sort of hand waving does a disservice to history. Initially the embargo was enacted because Cuba nationalized industries without providing fair compensation (a).
It's true that the embargoes have been more ideological since then, but the ideology is that fairly basic human rights (life, liberty, free speech) should be respected (b).
All that being said, the Castros are pretty entrenched. Maybe healthier interaction with Cuba would promote human rights faster. But you don't have to make straw man assertions to make that point.
a) https://en.wikipedia.org/wiki/United_States_embargo_against_...
b) https://en.wikipedia.org/wiki/Human_rights_in_Cuba#Political...
Basically Eisenhower shot himself in the foot by first rebuffing early advances by Castro that sent Castro head first into the arms of the Soviets, and then it just got worse from that.
It had nothing to do with ideology on either side, but with money and power.
I believe Castro was also pretty Marxist well before 1959. That would have constrained what any politician in the US could have done.
Except the US still has a number of trade embargoes in place with Cuba, so while they could ask for help it's possible the people they ask would be legally bound to say no. Lifting decades old sanctions that hurt both Cuba and the US (in hundreds of millions of dollars in lost export trade) would be something the US could, and should, do.
A trade embargo with a country on grounds of it being ideologically different falls under "interfering unnecessarily" in my opinion.