The funny thing is it wasn't just non whites. They paraded Gwendolyn around like she was the ultimate bad in the universe with some huge part in the film. So it seems it wasn't just non whites that got the short end of it. Phasmas part was significantly worse and underutilized than Finn. But hey, she had a cool outfit.
I'm sure the pre-Froce Awakens toy sales justified how little the character was ultimately used.