Why do you feel that you need to be able to see the point of it for it to be ok or non-offensive? Maybe you don’t see the point of it, but others see their own

Why do you feel that you need to be able to see the point of it for it to be ok or non-offensive? Maybe you don’t see the point of it, but others see their own point and don’t have to justify it. Should every possible characteristic a living entity can have also be a protected class?