How should I have responded if at all?

So it was just before Christmas of last year and I was getting my hair cut. I said something about how tiring to me all the decorating was and the hairdresser said, “well, I don’t celebrate so it’s a day like any other to me.” I was stunned. I had never heard anyone make such a relaxed, blunt statement against Christmas. What would you have said? I may have said, “oh” but I don’t remember.
I admit I felt a sadness like she was missing something beautiful.