Unfortunately the Health Code violation thing is a common misconception. Apparently there is no rule in any state that requires a person to wear shoes to patronize any establishement. There are rules requiring footwear for employees of certain establishements, but not the patrons. So the signs saying no shoes no service are only corporate policies and not health code reasons. Though many companies will use the "health code" as cover for the policy.

Now having just stated the above, I do not agree with mandatory bare feet at the checkpoint, because I feel it does expose us to unnecessary risks of infection.