No thanks. I don't want language restricted servers.
I think a lot of Japanese players don't like the fact that English speakers are playing on the same server, but the ones I've run into during behest have been quite content to do behest with non-Japanese players.
I think as long as we're respectful, the Japanese players will not mind being on the same server as us. Westerners have a tendency to be more....straight forward? Something than can probably be misread as rude. (And then there are the cases where people really are rude.)

I'm sure there are English speakers that want their own server as well.

Personally, I enjoy that the servers are non-language restricted. It gives a more global community feel when you log on and see people typing in Japanese, English, Chinese, German, French and so forth.