Is that in regards to people taking their shoes off and resting their feet on the carpeted floors or children crawling around on the carpeted floors? Even as a child that was something I didn't nor did I see anyone else do. Maybe those with minivans? No idea. Carpet sucks indoors but especially sucks outdoors and in cars and trucks! Nothing holds more foul stenches, stains, water, and filth than carpeting does. I know indoor shoe wearing in private residences is common. I'd say it's roughly a 50/50 split of households. There are some private residences I will not take my shoes off in either, for as you say, having white socks transformed to black in a matter of minutes - disgusting!