My surmise is that it was about the Castro regime's paranoia more than a desire to scuttle normalization. The Castro regime (then Fidel, now Raul) would love to see the sanctions lifted but will not risk their iron grip even for that desired goal. Raul Castro was then the armed forces minister and while more pragmatic than Fidel when it comes to issues of control Raul is absolutely ruthless.

I would love to go to a democratic Cuba, but as long as the Commies are in power I would prefer to travel elsewhere.