Kernel summit group photo

I wore sandals with socks (+ shorts) in my holiday-trip to London. And I did get few glances from salesladies in some stores. So why did I wear them? Because we walked over 10 kilometers a day, 7 days a week, and I wanted something comfortable. Blisters would have made the trip a lot less enjoyable. Should I dress uncomfortably in order to satisfy some arbitary dress-code? Mind you, the clothes I wear are neat and clean, so I'm not a sloppy dresser.