Asian Illusion

So... right now I'm working my way through "Gossip Girl" season 1. I know I'm like 3 or 4 years late, but I don't care. Anyway, I always find it blatantly racist that Blair's two friends Isabel and Kati are black and Asian (respectively) and barely ever speak, while the rest of the cast is white and has involved, speaking roles. What's worse is that Kati suddenly disappears and is replaced by "another Asian" named Nelly, who initially plays a dork, but is suddenly part of the group. Kati's disappearance is never referenced, and Nelly is just absorbed into the group. Anyone else notice this? Am I totally wrong, or is this actually what happened?