This is about Malaysia though. Indonesia doesn’t have sharia law except for one region, called Aceh. Homosexuality is not illegal in Indonesia though the LGBT do face intolerance from the state.
The west used to be all hardcore Christians and hated LGBT just as much as Muslims do today. Like homosexuality wasn’t legalized until 1967 in the UK. Before that time gay people, like Alan Turing, were chemically castrated. Change came because people stood up and fought for their rights and put their lives on the line. Not because everyone became atheist.