Rastafarianism is very much a minority religion in Jamaica.The main source of homophobia is nearly always said the evangelical protestant Christian denominations which are the main religions of what is quite a religious country. Buju Banton who became infamous for his extreme homophobia in songs such as Boom Bye Bye, directly cited the Bible as justification for his stance. You also have to Jamaica has been comapritvely violent place throughout it’s history.