It is a VERY fine line to walk, IMO. First, a person must not be in a very conservative environment because leather will be inappropriate in some workplaces no matter how it is styled, and better safe than turning heads. In less conservative fields, the skirt must not be too shiny, too tight, too short, too bright or even too noticeable. Unless one works in a fashion-forward industry, IMO wearing a leather bottom of any sort (skirt or pants) to work is just too risky. Even if no one says anything, if you caught attention in the wrong way it can affect how and whether you are able to move up in that company. Fashion just isn't worth that, IMO.