The most popular streamers in the world are all men, a male vtuber being entertaining isn't much of a stretch. Nijisanji has proved time and time again that there is 100% a market for male vtubers, the problem is that the only comparison we have is Holostars, and Cover botched the absolute the fuck out of them.
Cover fucked up the stars so bad that even if the male EN wave took off, Cover can't take advantage off it, they fucked up THAT bad with them, even now that shit persists with the most unpopular/disliked streams being the girls interacting with the boys( the recent Robo/Choco/Astel collab, the Mori/Rikka thing), cause of the schizo fanbase they've fostered.