People are emotional creatures. And in a place where a type of view is being actively promoted, it’s very easy to align those emotions in that specific direction.

An example here on Lemmy is ACAB. It’s anti-police and it posts the bad stuff that’s meant to show ACAB. They might say it shows the truth and people going through All, watching the videos and reading the articles might start thinking, huh cops seem bad. They keep going, read statistics and articles posted by other commenters and driven by this information, they eventually end up saying ACAB. Suddenly, anyone not saying ACAB is complicit, an enemy, a troll, part of the problem etc.

It’s the same for any politically charged social hub. It’s not just people who had the views but lacked a place to vent them, but people who are ignorant on the subject and are radicalized through emotional outrage. Emotional opinions are the hardest to change because the investment in them is the greatest.