Who Decides If Gay Is OK?

Why is it OK to be gay in the UK but not in Zambia? In 1967, a turning point for the gay rights movement in the UK, England and Wales decriminalised sex between men. Fifty years on, four out of five British people say they have no problem with homosexuality. Yet it remains a taboo and a crime in many former British colonies, including Zambia. What brought about the change in the UK and why it has not happened in Zambia, which largely inherited the British legal system?