This sounds like payback for that tweet warning mangaka about SJWs.

Maybe. They unfortunately will have some influence if they have some Japanese friends. From my experience the kinds of Japanese who hang out with foreigners will pick up whatever cultural cues and bias their "friend" has. They usually aren't political and take at face value what you tell them about American culture. (unless the foreigner is obviously mental like the fatty the other guy mentioned)

This sounds like payback for that tweet warning mangaka about SJWs.