Castro annihilated the land-owning middle class in the first years of his premiership [1], using the same playbook as Lenin wrt the Kulaks after the October revolution [2]: do away with the financially and thus politically independent asap.
Cuba consistently required Soviet subsidies to survive through the end of the 20th century [3]. That's all gone now.
[1] http://revolutions.truman.edu/cuba/aboutme.htm