Is there a reason why some expats don't want to learn the local language?

Hey, I thought I’d ask on Reddit since I noticed more and more expats working here who don’t speak German. I recently visited the restaurant near my gym to ask about the opening hours (since it was a holiday). The guy replied, “Okay, and now in English?!” as if I had made a mistake and needed to adjust. This also happened to me in different restaurants and shops where the workers spoke English. I hope this doesn’t come off as rude, and I hope I explained it in a way that some might understand. I know Zurich is very diverse, which I love, and younger people nowadays tend to speak good English thanks to social media (I’m 25). I know the local language might be difficult, but I don’t expect someone to be fluent in Züridütsch, but at least learn some basic Hochdeutsch or try to learn it. I read on an old Reddit post how someone said we should add English as our fifth national language. He added that it doesn’t make a difference since we already have four national languages, and adding a fifth wouldn’t make a huge difference. I don’t mind talking to someone in English, but don’t you think they should learn the language if someone moves somewhere to work/live? I travel a lot to Korea, and I’m also learning Korean because I know A: not many people speak English, especially elders, and B: I don’t want to visit a place or work somewhere and expect the locals to speak English to please me. I think it’s kind of ignorant not to bother to learn the local language because others know how to speak English anyway. I don’t know if I’m being a Karen or if some of you experienced the same thing.