You don't name them because sometimes you have had enough trouble. He has no more interest in Belize; so he might be right they have done all the harm they can to him there and it should be over. Lets further speculate that they were not just interested in harming McAfee, they wanted to extort money from him like he says.
What has happened. Well they have used what leverage they had to get what they were able to out of him. There interest was always money they got what they want, they'll now move on. It sucks for McAfee but if the system is as corrupt their as he claims than its a safe bet anything he could do get restitution would cost him more than he could hope to recover. He'd probably have to hire his own goon squad. So for him it may be best to leave it alone now. Let these guys move on to more accessible targets.
On the other hand if he starts naming names and cause unwanted attention to be paid to these people now suddenly they might find motivation to shut him up. These are the type of people who commit extortion and arson, If I were him unless i had some way to get the upper hand in the situation I don't think I'd be especially inclined to find out if they are above murder. I'd want to disentangle myself from them.
Know when to hold'em, know when to fold'em. Fighting is best left for conflicts you can win; and revenge tastes just as sweet cold.