Douchebags who put their sunglasses over their ears facing backward. Careful. They might break when I punch you in the base of the skull.
There is a very logical reason for it: When the weather is too hot for wearing shoes, but cool enough that wearing socks isn't too sweaty, a good cotton sock between your skin and the sandal straps reduces irritation. I did this for the long walks along the boardwalks in Atlantic City and Ocean City. Then when I went to the beach, I removed the socks so I didn't get sand in them. And then removed the sandals when I finally went in the water. Logic, FTW!
Bitch about it as much as you want, but it's the optimum comfort solution. And i'm not going to let the irrational preachings of irrelevant fashionistas dictate my level of comfort.