Don't jump to conclusion that anyone who says bad things about Yuna is a Mao fan. Maybe the same goes to a Yuna fan.
There are people online who hate both Yuna and Mao, who hate both Korea and Japan.
It seems they think it is much more convenient to them to use Mao's name to bash Yuna than to simply bash Yuna.
Judging from NMURA's past posts, he/she is not much of a Mao fan or a Japan lover.
It might be possible NMURA is a IMG fan (or maybe a S/Z fan).