Yuru Yuri was an enjoyable show but if it had a bunch of guys in it then the atmosphere of the show would have been ruined and it would've been worse for it.

There, I just explained why people don't want Homostars collabing with their oshi without resorting to any talk about idol culture or GFE. The simple fact is for most people vtubers have replaced CGDCT type anime and you can't have CGDCT shows with a sausage fest going on. People who watch NijiEN know the feel of it is completely ruined now that the homos will drop in on random streams and ruin the show.