Shoe removal on entering homes is standard practice over most of Asia, especially East and South-East Asia. Every home, including mine, has an abundance of house slippers just inside or even outside the home for residents and visitors to use. It makes sense. No one wants the dirt, mud, detritus and unidentifiable but suspect crap from the street (or unpaved paths is some places) inside their homes.
I remember one guesthouse in Thailand where the owner sat at the door all day and most of the night in case one guest dared to so much as put so much as one shod shoe over her doorstep. She would scream at offenders and have the entire guesthouse fumigated and exorcised if anyone ignored her.
But the best was when I was teaching in a Hunan university. All faculty and their families lived on campus in a special dormitory area. Shoes were left outside the doors as normal. As a pre-graduation prank, the students crept in one night and stole all the shoes then laid them out on the school basketball grounds in mismatched pairs. In the morning, all the staff were to be seen scuttling around in their house slippers attempting to find and match their shoes, all of which looked remarkably similar, while the students lined their overlooking dormitory balconies howling with laughter. Fortunately, most of the staff saw the funny side and no retribution took place. I was spared as I lived in a separate area.
Anyway, in order to remain on topic, I will add that I've never heard of anyone having a foot accident in a domestic kitchen in China, although I supposed it must happen sometimes, but not enough for it to be considered an issue.
