http://en.rocketnews24.com/2015/09/04/its-the-japanese-run-overseas-gamers-tired-of-playing-splatoon-with-inklings-from-japan/

Maybe its just me but I haven't noticed them being any better than any other players. Or maybe I haven't played higher ranks as I am at B. I have played in rounds with more Japanese and have held my own. 

These guys could.. You know... Get good at the game?
I know, an alien thought. But hey, it MIGHT actually work out well!
I've played with my fair share of Japanese players and I've won as much as I've lost.

All I have to say to those people is: git gud.

It's not that hard.

Sounds like a bunch of excuses, keep playing and learn the game

Makes no difference to me where they're from, just give me a challenging match.

I've not noticed japanese players being noticeably better than others... I think this is just selective memory and confirmation bias.

I'm tired of lags from Japanese Splatoon players.

I tend to lose in Splatoon regardless of who I play, so can't say I've noticed anything.

We should be thanking them as without em wait times are twice as long.

Well the end of the world will have new episodes of the Supernatural, Cockroaches and 20K more copies of Splatoon sold in Japan. There's no stopping it.