The babes in Nigeria also straighten their hair. Do you really think they are trying to deny their heritage?
People from Nigeria are highly known for their elaborate braided hairstyles. I'm not saying that nobody in Nigeria straightens their hair. Not at all. But, if you look at the beauty salons in the US, the African ones tend to specialize in hair braiding while the Domincan ones more or less specialize in blowouts and getting the hair straight.
How common is it to see cornrows in the DR? Aside from the Haitian hair braiders along the beaches.