Why would South Korea use ASL and not KSL? Why would South Korea broadcast their news in English and not Korean for their Korean-speaking population? They are

Why would South Korea use ASL and not KSL? Why would South Korea broadcast their news in English and not Korean for their Korean-speaking population? They are providing KSL because most countries have their own localised sign language. Australia has Auslan, the UK has BSL, South Korea has KSL etc.