Yes, but how many get injured in the build-up or on race day? See reference to previous study on injury incidence and contributing factors. No-one is saying that everyone should run barefoot, just that we don't need the cushioning/support that the running shoe industry has brainwashed us into thinking we do.
We are not "designed" to do anything but we have evolved a very effective shock absorption system that only works optimally if the foot is able to flex freely and interact with, and adapt to, the ground. We also evolved to run on hard baked savannah which is equally as unforgiving as tarmac.