You never have to worry about ruining a good pair of shoes because you got paint on them. Bare feet can be very practical.
plus you get coloured soles. still remember when I painted and decorated my mother's bedroom. sky blue feet for a week
And you can also get some colorful bare footprints on the wall! Sounds like a nice idea for some extra pizazz when painting your kids' room. They'll surely look far more awesome than some ordinary handprints!