I work in a place where we get lots of visitors popping in and out, part of my job is to say good morning/good afternoon as they enter.
The language of my workplace is Welsh. Every member of staff is fluent. The place in which I work is a place to learn about Wales.
I say "Bore da" with a smile, and get a "err hi" "morning.", or my fave, nothing.
Often with a face like I've just shit on their shoe. Perhaps sometimes even a hint of disgust.
AIBU unreasonable to expect people to answer me in Welsh? Then speak to me in English if they please afterwards?
Would you go to Spain and answer in English, if a shop keeper etc greeted you? Certainly not.
Even some Welsh seem to do this, but 99% of the time they are English.
Many Australians, Americans, Canadians, other Europeans put effort in and reply "bore da", "prynhawn da" etc.