Definitely the case, I had a few N/A players rage quit when they themselves made the mistakes. I recently had the chance to be with a tank that doesn't know how to aggro and maintain it. He also dies with every opportunity even though the healer is by and large competent.

At the end, he cursed us to high heavens and then told us to find a better tank if we thought he was that bad. All the other members surrounded him and showed /doubt. He then promptly quit. Hilarious.

I just did a good run of Aurum Vale. With a group of Japanese. It was efficient as all hell. Lots of bowing, welcoming, cheering and tips with every boss. It was definitely better than any and all N/A servers.