Among the reasons Cuba has lost its lawsuits is that its entire cigar industry is built on assets that were seized from private owners. Judges in countries under the rule of law have a real problem with plaintiffs who want to invoke the rule of law outside their borders while historically and actively dismissing the rule of law within their borders.
I suppose I can understand that. "Hey, Altadis is stealing our name!" Hey, fucker, you stole it, too. Zip it. Case dismissed.
Which, as I'm looking at what I can find on the case law, is pretty much it. That, and the legal doctrine that says "No one in the US is going to think a cigar for sale in the US with the name 'Cohiba' is from Cuba, because everyone knows Cuban cigars can't be sold in the US.
This, of course, sounds utterly ridiculous, but has a sort of perverse logic.