At risk of committing all kinds of teleological fallacy...
... the barefoot principle makes sense from an evolutionary PoV. It's possible that running shoes are an enhancement - but it's also possible that they force your legs to work in a manner that's not biomechanically native to them. For at least some people, I can see how that might generate a problem.

I can only go on experience - and I did, previously, have expensive running shoes, extra support, and all that malarkey - but my running, and my legs, feel better now.
( Enzyme is powered by sunlight, Wed 15 Jul 2009, 15:10, 1 reply)

Also from an evolutionary PoV
I've heard before that the reason most shoes have thicker heels is to provide additional padding to compensate for the harder surfaces we now walk on (concrete, tarmac etc) compared to the earthy, softer surfaces. Our bodies evolved walking on far softer surfaces, as a rule, and we've yet to physically catchup to match the environment we've created for ourselves.
( LemonEntryMyDearWatson This time, Moriarty, the hand is on the other foot, Wed 15 Jul 2009, 15:51, closed)

Not sure about that.
A baked savannah can be pretty hard...
( Enzyme is powered by sunlight, Wed 15 Jul 2009, 16:07, closed)

However
a baked Alaska is much softer.
( K2k6 has a proper job these days, Thu 16 Jul 2009, 12:08, closed)