Why can't African-Americans have naturally "Good Hair"?

I'm African-American. I am constantly hearing this stupid term "Good hair" in the black community. I was in school one day talking to one of my friends (she's black as well). She brought up how she wanted to marry a white man so that her baby can have "good hair". It made me really angry, but I didn't say anything. I actually cried one night thinking about how many African-Americans hate our NATURAL hair. I guess it just made me feel really insecure. I also remember a time when I was watching Roots with my mother. She didn't compliment ANY black women's NATURAL hair until she seen a biracial women who was half black half white. She said "Oh, she has pretty hair" That too made me very angry so I said "I think everyone has pretty hair, you just have to take care of it". I can't explain how much I hate hearing them say that. I know that this issue traces back to slavery, but isn't it time we move on and stop believing the degrading things they said about us? Everytime you say things like that African-Americans, you're insulting yourself and a whole race of people. So my question is why can't an African-American have beautiful and natural "good hair"?