Derbeno wrote:"main place for afro-influenced culture outside Africa " is quite a statement when you consider Haiti, Brazil, Cuba, DR, Columbia and Venezuela coastal region, Tobago, Carriacou, Surinam to name a few

Exactly, Brazil, Cuba and that's not even mentioning the USA which has flooded the world with Rock & Roll, Blues, Jazz and Gospel. Each of those art forms (individually) have had far more cultural impact on the rest of the world's music than everything put together that has ever come out of Puerto Rico.
The styles of Puerto Rico don't fascinate or intrigue me at all. Bomba, plena, jibaro, etc. just don't have the compelling groove or intellectual composition that Cuban folklore and later genres have.