You keep your socks on so that's not really an issue. I personally don't let anyone wear shoes in our house, I don't know what they've stepped on so I don't want them dragging anything over the floors and carpets.
Don't even feel like discussing how clean are fresh are everyone's socks.
Agree socks might not be 100% clean but you have to draw the line somewhere, and the bottom of a sock is bound to be cleaner than the bottom of a shoe.
In central Europe it's common to have a special room called checkroom/garderobe next to your main door where you store several pairs of guest slippers.