Discrimination based on things people have no control over, that's bad. Discrimination based on things people do have control over, is reasonable.
People choose to get tattooed, even if it was a rash decision made in a drunken stupor twenty years ago. Getting something discreet that can be covered up is one thing, getting something prominent that is clearly visible while wearing professional clothing is another. If you do have tattoos, be prepared that high-profile companies such as jet operators might not be that keen on having you as a public face of their company.
But you knew that when you got the tattoo, right?