> I see it a lot

If so, you should be able to find three examples. Can I please see them? Specifically, three comments that aren't in any way rude, downvoted for expressing an unpopular view?

The reason I'm curious is that I try to watch out for that, yet have only seen one comment recently which seemed to me downvoted purely for expressing an unpopular opinion, and even it was somewhat borderline.

> You're training people not to say something others disagree with.

That's not true if most such comments get more upvotes than downvotes.