Why do laws against homosexuality vary between culture?
Religion - Christianity, Islam and Judaism condemn it.
Countries where law making is influenced by religion will more than likely make it a crime.
Public opinion - where religion has a strong influence - 95% in Egypt believe homosexuality should be rejected but others such as Russia do not.
Sexism - male homosexuality is a crime in more countries than lesbianism - due to sexist assumptions by male law makers - women were incapable of same sex attraction