There was this guy I met at the dog park who talked nicely to everybody, especially to the ladies. He would be the kind to always greet you, offered to share his snacks. He seemed to always be at the center of the conversation.
He tended to orbit around my now gf and for a long time he forcefully sticked with us, all good there at the beginning. But as soon as I started going out with her his behavior changed. Instead of being a direct ass to me he tried to monopolize my girlfriend's attention, being overly attentive, stomping over me when I was talking, always trying to dominate the conversation.
Now, his true color started to show when I confronted him when he was trying to impose his lifestyle on others.
He attempted to get a mutual friend to drink with him, which is by no means bad, the problem was than this mutual friend was a recorying alcoholic.
He tried to coherse her by using social pressure, saying that you should enjoy (which is true, but he doesn't get a say in how anyone else "enjoy" THEIR LIVES), but I standed against it. The few times we drank together I was able to keep her from overdrinking, sooooo he started to invite her without acquaitances.
Long story short:
He got our mutual friund hooked again to the point of losing her job.
I untintentionally got the best of him, such as "women are less value than the historical sites they destroy in feminist rallies" and regarding his own girlfriend who doesn't want to have kids "she is to young to know that". He once asked this out of nowhere "how old do you think they are?", whes referring to two teenagers who were clearly 15 at best.
It turns out that majority of the dog owners dislike this guy. But, no one ever said anything because we all thought he was well liked in the cammunity.
There's a thing called the Abilene paradox. A family is hanging out when one of the suggests having dinner in Abilene. It's a hot day and a long drive, but nobody wants to be left out, so they all agree. After a terrible dinner, they all reveal their frustrations at the event when the person who suggested it notes that it was the first thing they thought of, as they thought everyone else was bored.
Thus, everyone sits in wonder at how they all convinced each other to do something nobody among them wanted to do.
It's fun how often that includes hanging out with someone.
Abilene paradox doesn't exist. That's a failure of communication and a benign dishonesty with each other. State you're bored and check the room before making everyone go on a journey. Get to an understanding before making plans.
Person A wanted to please person B and suggested a given action. Person B assumed person A wanted that action and wanted to please them, so they agreed. Nobody wanted the action, nobody was forced to take the action, everyone had a chance to deny the action, nobody even necessarily lied. People wanted to please others and everyone did something nobody wanted to do.
Yes, it is a failure of communication. Specifically, it's a false consensus, where everyone misunderstands the opinions of the wider group. Even more specifically, it's the Abilene paradox, where everyone acquiesces to the misunderstood desire of the wider group.
In the specific context of the OP, nobody liked the guy, but everyone thought everyone else liked the guy. They didn't want to openly insult someone everyone liked, so everyone kept quiet, so nobody realised nobody liked the guy and nobody told him to go away. It's the paradox in action.
I guess I still misunderstand because it still sounds like no one asked any questions about why or whether it was of interest. Mindless following is only a paradox when sensibility is regained and someone asks basic questions.
No one should ever mindlessly follow a group. That's how people follow GPS into a lake when common sense should alert them far before catastrophe.
You want others to like you. You want others to be happy. You put your own desires aside for the benefit of another. It's not mindless, it's selfless.
You make an assumption about a person, and they never give you cause to doubt your assumption. It will take you a long time for you to think your assumption might be wrong. After all, they agreed to it, so they must enjoy it, right? And they invited you to do this thing they like with them, so you don't wanna bring the mood down by refusing.
It's obvious in hindsight, or from a third person omniscient perspective like we have, but in the moment? It happens. It shouldn't, and that's why it's a paradox.
See also: Peer pressure, false consensus, "Don't rock the boat"