Basically it's impossible for black women to have straight hair if they continue to get their hair done all the time. If Beyonce put heat/chemicals to her hair every time she needed to perform or make a public appearance, her real hair would fall out, it'd be so fried. So it's actually practical for her to wear weaves/wigs to protect her natural hair.
I don't believe this is true. Zoe Saldana has naturally coarse hair but seems to have a relaxer and has been wearing her hair straight for many years now. Oprah revealed that her stylist straightens her hair every. She even had pics of her naturally coarse hair-- which is very thick and long. Everyone thought she had wig or weave but all her hair is her own. Some celebrities do wear wigs to protect their hair from stylists who don't know how to care for black hair properly.
Here's Oprah's hair in its natural state.
hairstyles53
Straightened hair
I saw the episode where Chris Rock was promoting Good Hair. He didn't believe Oprah's hair was real so she let him feel it.

