Is gingerism the last "socially acceptable" form of prejudice?

Racism - bad

Sexism - bad

Homophobia - bad

Islamophobia - bad

Fat shaming - bad

Skinny shaming - bad

Yet it seems to be perfectly "ok" to discriminate against someone that has red hair, why? Of course, people with red don't face the same prejudices that a black person would for example, but they still have abuse hurled at them in many areas of their lives.

If you don't have red hair, do you feel you have an understanding of the issue? Or is it the same as a white person can't truly understand how a black person feels?

If you have red hair, have you ever had anyone be prejudice towards you? I know I have.