Your information is two things. First it's outdated. In 2013 Cuba opened its borders to external travel by Cubans. In that year about 180,000 Cubans traveled abroad. "The average Cuban traveler is a professional between 25 and 40 years old who's scoping the international job market without renouncing the benefits they receive in their home country. The reform allows the extension of travel permissions from 11 months to 24 months before a Cuban citizen living abroad loses the right to universal free health care and education." - International Business Times

Second, it's absurd to suggest that the USA remained in a 55 year state of barely-suspended war against Cuba because it didn't let its citizens travel abroad.