...and some folks run marathons barefoot.
I suspect one should not just jump into this, I believe you need to slowly build your feet up to the new environment.
If you are a frequent hiker, and if your feet are used to ONLY shoes and boots and you have built up callouses on your heels and you switch over to sandals, you run the very real risk of having the callouses split causing much discomfort (to say the least). I personally have seen this happen on many occasions.
just my 2 cents