>>34118836It didn't, most idolfags just prefer that their oshi is dedicated to their fans first and foremost.
If they get a boyfriend, it's naturally expected that she'd be more dedicated to him, which is not ideal (there are some idols who actually make this work though).
"Unicorns" as stated in this thread or in general are a very VERY small minority. Most Holofans are CGDCTfags and can often enjoy Homo streams on their own merit, they just like the cute girls vibe which gets trashed when there's a male on the screen interacting with the girls in a non professional/casual way.
There's also gachikoi who are unironically in love with the chuuba and don't want to hear about their irl relationships on stream, but don't mind it if they do it privately as long as they don't blatantly flaunt it on their roommate accounts.
This sort of nuance does not help when trying to build a narrative of "Hololive fans hate male collabs because they're incels" and so both the other majority groups get framed as being "unicorns" so that they can be attacked with the same label.
People are generally too retarded to know about human psychology and stuff, so when someone starts an argument and frames everyone as unicorns, no one questions the framing, which allows the twitterfags to continue pushing their narrative.
Just remember, if anyone is using "unicorn" unironically, they are NEVER arguing in good faith and are trying to push their twitter narrative here.