That kind of polarization does not just happen for no reason; people reach that frustration after repeatedly seeing themselves and others being downvoted anyway, no matter how flowery and sugared their dissent is.
Downvoters don't care how polite someone is, if they're saying something they don't want to be seen. It's a zero cost action for them, and easily lets them control what opinions other readers see about a topic.
Example: In every thread about browsers, if most people say they dislike Edge, anyone simply saying "Hey I like Edge, it's not so bad" gets downvoted.
So after a while that Edge user will be preemptively defensive the next time they voice their opinion, if they even feel like participating anymore.