I think you should and I have, each time, but many people don't because "they can live without it" and either "they don't have time" or "they are just not good at languages". Also, keep in mind that many people who claim they don't speak the language, or you've never heard them speak so you assume they don't, actually can, but they are just not comfortable speaking so they refuse to speak when not absolutely necessary. I was like that with French because I thought my pronunciation was really bad and what were the people going to think. Indeed, my pronunciation was far from perfect, and again, it is true that French natives are generally not very forgiving towards people mutilating their beautiful language. So the attitude and support of native speakers is also an important factor.