We used to run sockless all the time (late 60's-70's), the only exception being very COLD weather in winter.
Some still do. Back then most shoes weren't built up as much as they are today (usually weighing 6-8, with 10 oz.
being considered a bruiser) and I for one thought nothing of tossing them in the washer if they got gamey. The usual shoes were the very early NIKE and the classic Onitsuka Tigers that you got from Blue Ribbon Sports.
Today shoes cost as much as $100, which in my opinion is shameful (how much money do you need Phil?) so it's far more of an investment I suppose.