When I grew up a half of century ago in East Europe, keeping your shoes on when entering a house was still considered as an unacceptable behavior.

However, later this changed, in good part because much of the population moved from bigger rural houses to smaller apartments in the cities. In a small apartment, there was not enough space to have at the entrance a big enough wardrobe with dedicated places for the visitors to store their shoes, and to provide slippers for them. Moreover, a small apartment was easier to clean after the visitors left.

Thus the customs changed, and it became normal when visitors came and attempted to remove their shoes, according to tradition, to assure them that there is no need to do that. Nowadays I think that few remember that in the past it was really mandatory to never enter a house with your shoes on.