@georgeob1,
When I say that the embargo backfired ideologically it is because it was shrewdly used as an internal propaganda tool to mask the inefficiency of the regime's economic system. It worked for at least two decades. In the late eighties, when Soviet subsidies were there no more, Fidel talked about a "double embargo", both from the US and Gorbachov's Soviet Union, to explain the situation. An economic collapse ensued.
I don't think the embargo has played an important role in Cuba's economic woes (perhaps only in its first, crucial, years). It has since helped the Castros ideologically and the place of potential American investors has been taken over by European (mostly Spanish), Canadian, Latin American (mostly Mexican) and, lately, Chinese firms. US interest were not served by it, in my opinion.
What interests has the embargo served? The ideological interests of Conservative Americans, who think that "muscle" is better than sound diplomacy. And the ideological interests of hard line Communists in the Island, ready to stand against the epithome of Capitalism.
I believe that free markets and personal freedoms are intertwined. Cuba has to move, compulsory, to a Chinese style model. It will still be authoritarian, at least for a while, but certainly a welcome difference from the hellish Police State they now live under. Just compare China, and its limited freedoms today, with China during the horrid Cultural Revolution of the sixties.