... The cons:
Pubs -most pubs won't let you in barefoot.
Grip - barefeet don't get a good grip on things like wet wood
Stonebruises - if you slip and step hard on a stone, it can give you a very painful bruise.
Thorns can be painful (but if you do this a lot, you'll end up with thornproof feet).
Mmmm, also
in hot countries jiggers and other nasty creatures can be a problem,
in temperate climates ticks and chiggers also,
in cold climates bare feet are prone to going black and dropping off,
and whether you have any of these problems or not, you can't easily take off your feet before getting into your sleeping bag.