I can kind've understand this for a twitch thot or whatever else, after all the sell you the GF/softcore experience, but for v-tubers? Outcast girls who have purposefully made their streams about their personality, abilities, and entertainment value -- going so far as to divorce themselves from their female body?
Is it an unproven necessity holdover from Idol culture? Is it to do with Japan's view on virginity and femininity? Is it that a large amount of men really do view them as lovers? Is it due to a small but wealthy segment of viewers? To simplify the question: do you think the average Holo would lose viewers over attaching their lovelife to their character's persona?

Now, regardless of if this stigma actually has reason behind it, how do you personally feel? I, for one, actually enjoy women talking about boyfriends. Not when they're talking about assholes, normal dudebros, or anything like that, but when it's about men they absolutely dote over who're described like a dream. I'd be happy to hear Watame talking about a kind guy she really loves who means the world to her, and hear about what she does for him and what he does for her.
It's a good feeling to know two good people are making each other much happier. Especially when you enjoy both of them. If you're sexually interested in your girl, I can kind've understand it, but I'd ask you to get away from V-Tubers if you have that kind've negative impossible trapped one-way relationship.

Of course this isn't the same as hearing about the girl's riding a cock carousel of shitty ex's. Nor is it the same as making the streams about their personal life/relationship.
But streamers in the west have used relationships as an enhancement mechanism, part of what drives people to their streams -- is this an untapped market for V-Tubers? Surely there's a demand for talented outcast girls, whom you can connect with, finding love and happiness with guys you can likewise connect with.