We had the book study at our house for a long time and never removed shoes. It just wasnt the custom in our area I think. After my parents got new carpet put in some people started to remove their shoes but it was never a standard thing and we usually had ours on. On the days I went to other peoples house for the book study or service meeting we didnt remove shoes either. There were always a few who were brought up with that tradition but there were just as many who didnt.
I agree its a cultural issue.