>>50589047People operate on irrational values, but that is a completely separate issue from maintaining logical arguments. I don't know why you're conflating the two.
All of the things we're discussing here are irrational emotions/values. So you want to know why people are upset when streamers interact with a male, right?
I guess the easiest way to put it is that the feelings involved are essentially equivalent to feelings of romance and affection in real-life relationships. Maybe that's impossible for you to understand since you've never felt such things, but it can absolutely happen, I hope I don't need to prove that to you. In Japan, "gachikoi" is a well-known thing in idol fanbases. It is a given that there's a subset that feels this way toward the idol. And certainly it plays a part in their support for them. It can thus become a symbiotic relationship in which the idol caters to her fanbase by doing stuff for them (singing, chatting, etc) and in exchange they provide her with money and support, hoping to propel her into stardom and achieve her dreams of becoming an idol.
Now it's one thing if the talent straight off the bat says she's in a relationship, or something of that nature. So why aren't they, why don't those statistics in vtubers follow regular relationship statistics? Why are literally all of them presenting as single when statistically more than half of them shouldn't be? Because women aren't stupid and know that being a cute single woman is a draw to attract people. And if one is deliberately doing such a thing, then it would be deceptive to actually be doing something else behind the scenes. You can't have you cake and eat it too.
This is where unicorns come into the picture, they simply expect women to follow that expectation fully. If they're acting that way, then they should be that way. They shouldn't be deceptive about it and should respect the people that they draw with that appeal, the product should be what's offered. Playing with people's feelings by playing around with guys is considered disrespectful and messed up. Not even necessarily for themselves, but for others who they know will feel bad about such things. It triggers the bro code, where you feel bad for the guy you know is in love with the girl.
That said, everyone is different and while most people will have the dignity to leave if they lose respect for the talent, there are ones who will be obnoxious freaks. This is a separate character issue. Some people scream and moan when things don't go their way, others don't.