I'm Asian myself, but most defiantly wrestlers such as Japanese and Chinese that don't know how to speak English will hold them back. I agree wrestling is based upon the in-ring work an individual, tag-team or a unit does, but you can't forget other factors such as mic work and how well one engages with the audience.
It's defiantly hard for Asian's to become top-talent within the WWE due to the language barrier, it's sad, but it's reality.