No Chinese people in that place...

Why is it that people aren't quite so keen on the idea of a restaurant that sells regional food not having its countrymen working there?

Wagamamas is a Japanese restaurant that's quite big in the UK now, and to this day I have never seen a single Japanese person working there. Does it bother me? No! Does the food taste brilliant? Yep!

Does it ruin peoples' authentic experience of a restaurant? Would they prefer the menus to be in Japanese as well?