>>54213696It unironically came from young male athletes before idols were even a thing.
Since having a girlfriend requires you to spend time and it would distract you from training, it was not unusual that the big baseball teams would have a ban on the boys having girlfriends, and being seen outside of the camp fooling around with girls (even if there wasn't anything sexual going on) was basically frowned upon (fans would think that the boy isn't taking this as seriously as his colleagues, and it would also impact on the image of the team). You could make a parallel between them with monks, that would also practice celibacy, and not give in to carnal desires.
Fast forward to late 90s/early 00s, during the initial boon of young idols (initial idols weren't young girls), many companies adopted the same banning culture, and even at the time, some people were skeptical of the true motivation behind it. Regardless, the ban still made sense for most, being that idols were held to an even higher standard of pureness, where they can't swear, they don't shit, and aren't interested in having sex, anything related to love is in the most platonic sense. Some cases of idols being seen with boyfriends in love hotels and the like would even be on the news.
And now we have the unicorns that comes from the mythical legend that unicorns hates women who are not pure of heart.
But just like the culture behind it, aside from the most extremists of the unicorns, even the unicorns are fine when the interaction is strictly professional, and basically don't just look like a couple having fun together (as that would seen as impure).
All of this "problem" comes from the western culture basically having nothing like that in the past, the closest thing I can think of are priests and nuns that also devote themselves to something else and thus, are not permitted to give in to worldly desires like sex, but it would be a long bridge between that and vtubers.
There is also the fact that most of the western audience doesn't understand the whole "idol" concept, and they are only seen as entertainers, which are sometimes famous for the opposite, where they have extremely unstable relationships and are always somehow involved in drama about their ever changing relationships.
Either way, Nijisanji kept walking on the entertainer road, while Hololive found success on the idol road. And despite Hololive sometimes being seen as this big bastion as to what idols are, true real life idols have much harsher standards, to the point where many times Hololive staff themselves wonder if their talents can even be called idols (as that could be an insult to real life idols).
And despite Nijisanji sometimes being seen so crude, even their staff have standards for what entertainers do too, just look for the SKB deleted stream.