Many employers often discriminate on their current and potential employees for things like hair color, piercings beyond ear piercings, and for tattoos (and not even tattoos of offensive content). Why is this important? Why is this relevant in any sort of way?
Because a person with a nose ring and a tattoo of a dragon, their dog, or a symbol of their religion, and possibly blue hair is still a human being and should be judged on their work ethic, and work experience or willingness to learn.
Sometimes, it's not even something as complicated as a person having a piercing, tattoo, or unconventional hair color. Sometimes a person is missing teeth or has acne. They might still be turned down for looking unhygienic, even if they really aren't.
Appearance-based discrimination needs to end.