Where I work, I"m expected to dress a certain way. I can dress "better" than the expectation, but I can't dress worse than it. It doesnt' bother me. It's the business's right to ask their employees to dress and conduct themselves in a certain manner.
If you work in a machine shop, you're required to wear steel toed shoes. If you work on a highway crew, you're required to wear orange. If you work at at Scores, you're required to wear nothing.
What's the difference with requiring a helmet? For the people getting their panties in a bunch about it, choose to work somewhere else where a helmet isn't part of the mandatory dress code. There's your freedom of choice.