I believe there are ancient reasons for this prejudice. People with red hair were believed at one time in history to be witches or something. I think it has its origins in that.
Yes it does...it also stems here from the England Vs Scotland history.
I have auburn hair and I dye it redder all the time. I personally have had no comments about it other than what a lovely colour it is..and people try and dye their hair auburn all the time..so it can't be that bad

My Area Director has two girls who are bright ginger and they are gorgeous

but my AD is always commenting that she has trouble finding clothes that doesn't clash with their hair..most girls clothes being pink..and for her thats a complete no no.
I think with Ginger boys..there is a stigma that they are going to be mischievous..where it comes from I don't know..but thats the impression I get. I know everytime my brother was naughty my Gran used to say "its because he is a Ginger Nut"
I like being a redhead because I am associated as having a fiery personality..and they would be damn right too

We are assumed to be great in bed, fiery, sultry, can deal with life's crap with ease, good conversationalist, brainy, arty and fun....Well I like all those characteristics...so I like my hair.

Quote I like:
"Blonde's may have more fun, brunettes may be brainier, but when it comes down to raw energy, creativity, and personality ... you just can't beat a redhead well, you can, but beware ... she'll probably beat you back!"