Obama didn't have his fellow-citizens shot by firing squad without a trial merely because they were political opponents, like journalist Yvonne Conde's uncle [1].
Agreed the sanctions were unproductive. More than anything else, US sanctions helped Castro stay in power for half a century.
But to blame the sanctions for his atrocities - or to say the good he did outweighed the bad - is to be willfully blind: When Cuban government ships spotted a tugboat full of refugees headed for Florida on July 13, 1994, they blasted it to pieces with high-pressure fire hoses. “Our tugboat started taking on water,” recounted one of the survivors, María Victoria García. “We shouted to the crewmen on the boat, ‘Look at the children! You’re going to kill them!’ And they said, ‘Let them die! Let them die!’” Forty-one of the refugees did. [2]
While you write about the good things he did from your comfortable home with high speed internet, with the rule of law in a capitalist liberal democracy, this is how desperate his citizens were to leave this country of “good things”, and how barbarous was Castro against his own people.
[1] https://twitter.com/YvonneMConde/status/802587003057410048
[2] http://www.miamiherald.com/news/nation-world/world/americas/...