Heck no! Make a neutral dress-code or don't have one. The saddest part is that I am not remotely surprised we are debating this sexist nonsense in 2016. Women still don't get paid the same as men, and are still penalized for having children.
https://www.buzzfeed.com/laurenstrapagiel/bloody-ridiculous - here's a good reason why heels in the work place are a bad idea, and why requiring them is asking for a lawsuit. (Oh, yea, graphic pic of bloody toes if that bugs you)
And ugh at the bloody stupid argument of 'well you knew when you were hired...". Yea the 10 year old kids who work in factories know that when they get hired. Military people knew that DADT was law when they were hired. It doesn't make it right. It is absolutely not a reason not to try and change it, either. A lot of stores and even government offices make policies or laws that are contradicted by other laws. It is important to fight them, and change them. And, in most cases, the only people who have the standing to do so are people who suffered under them. So not only is that an intellectually lazy argument, its also legally wrong.