Not a ruffian but I do hate when other languages use other languages. It's like, if I watch an Indonesian girl, I want to hear their ugly ass language and try to pretend I will learn it to understand them. Same with EN, every EN member tries to pander to the Japanese audience, some more than others. I came to watch an English stream, not have to read chat to find out what someone says, in that case I woulda moved to a foreigners stream like the jp girls or something.
Never made sense to me. I understand the medium is japanese culture and what not, but this is why I don't watch vtubers anymore, stick to the language you was born in or applied to or fuck off, its that simple desu. Want to be jp? Then should applied to the jp branch, oh im sorry, you couldn't get in because you're not good enough?!? Then don't hide in another branch, it's stupid.
Again I'm not shitting on ruffians or anything, this is just a common issue in vtubing, niji and other corpos and indies are just as much guilty.