>>18158635"The whole appeal of vTubers is that they're characters"
Well actually, it isn't. The appeal is that they're anime waifus you can interact with. There is also an assumption that most of what you're seeing is at least "partially real." Remember these streamers are giving us constant anecdotes about their lives and doing their best to convince us they really do believe the things they are saying.
People inevitably buy into it if the streamer is good enough, and so when it inevitably turns out that the person they're seeing on the screen is just an illusion and really is just "someone playing a character" and the person they liked doesn't really exist, they feel hurt and betrayed.
This may seem crazy to you, but it's how they make their money. Sure, the average fandead who watches a couple of streams a week probably wouldn't care, but this is going to devastate Rushia's subs and SCs because of those lonely otaku giving her their money because they felt like they had a close relationship with her are going to take their cash to someone who can maintain the illusion better.