I found women typically smile, ask a question out of genuine interest, or make a positive comment.
Snide remarks, snarky questions or odd looks typically have come from men.
I bet that's because those men are jealous. They'd like to try it but fear about other people making comment and thinking they are... Gay, maybe?
I my case, most people does not seem to pay attention to my bare feet. Just some stare at them when I pass by and only a few make a comment —either out of amazement or creepiness.
And there are also the children, who usually shout out loud "woah! He has no shoes!"