Unreasonable procedures

The casino has an entrance that leads to the mall, which is open to the public. Together with my children, I made use of this entrance today on my way to the mall. We have used this entrance countless times before. Today however we were stopped by a security guard and told that we were not allowed to enter due to the fact that my children were not wearing shoes. My children are preschoolers and very rarely wears shoes. This is one of the most absurd procedures that I have ever heard of. I would love an explanation about this.