A rule that permits a moderator to remove something because its “not unpopular enough” is not a rule. Its a suggestion. And while this is certainly one way of approaching moderation, this style does tend to create a lot of discontent in users.
At the end of the day, Reddit moderators are unpaid volunteers. When the standards for Reddit moderation are : have no job, no life, be willing to wade through literal online garbage 24/7, and do it unpaid, you’re going to get exactly what Reddit has. Terrible moderators that go on power trips constantly because of tantrums, and a very very tiny fraction of people who do not value themselves enough.