Snarky comments aside - what about discretion and outward appearances?
While it's wonderful that they are enforcing a dress code for their employees for the sake of an outward appearance, at what point is that appearance utterly destroyed and made unpleasant and off-putting?
When you're chastising a human being - one which other pax cannot easily infer is a UA employee - openly infront of them.
If you're going to keep up appearances then you need to learn the art of discretion and that being confrontational and critical of your employees infront of your guests is a bigger no-no then denim in the F cabin.
Keep the downward spiral UA, you'll get to the bottom eventually before it falls out.