Are you just making a specious argument, or are you literally arguing that acting in accordance with one's values will cause bigger problems than engaging in addictive behavior?

But in moderation (heh), eating vitamins is much, much better for you than eating potato chips.

Nobody's arguing for an excess of anything. Obviously a completely locked down subreddit that rejects and deletes all posts and comments would be useless, but so would one that's completely unmoderated.

The thing about metaphors is that they're just metaphors, not equalities.