Today let me pull up a really old Dennis the Menace comic, dated June 30, 1964.
Dennis the Menace, June 30, 1964
It’s interesting that since the time of that cartoon, keeping horses barefoot has become an item of interest. Here’s the Wikipedia article: Natural Hoof Care; and here’s an article on Barefoot Hoofcare.
And if Dennis is concerned about the poor barefoot horses, what about poor barefoot Joey?
Ahcuah 
That looks really dangerous, being the target like that, or even standing next to it. It’s making me cringe.
What are they doing?
You’ve never seen people play horseshoes before? You have two stakes 50 feet apart. Each player get two horseshoes. You stand at one stake and try to hit the other stake with the horseshoes. You get one point if it touches and two if the shoe goes around the stake. We played as kids and no one was allowed to stand near the target stake for safety reasons.
They do seem to manage pretty well without huge lumps of steel nailed to their feet.
I think the Romans introduced horseshoes because their roads were too hard on horse’s hooves. Barefoot horses have to stay off some surfaces. I don’t think they can do city patrol.
The other thing to keep in mind is that a horse’s hoof is basically a toenail, which grows at a fixed rate. So on such road surfaces it can wear down faster than it is replaced.
With humans, the more you stimulate the sole, the faster/more the skin thickens. (You can still wear it down too quickly, but it is less likely, I think.)
Haven’t you said in the past that you have to be careful on tennis courts?
I’ve found that wet sidewalks really slough off extra skin, though not to the point that my soles get too tender. Not so far, anyway.
Yes. However, my soles really don’t get all that much stimulation from uneven surfaces, particularly in the winter when I don’t go hiking enough. If I were out there every day, my soles would regrow much faster and I think stay ahead of tennis losses.
And yes, wet sidewalks (or just wet sandstone) can really sand off the skin.