I spent a large part of my formative years on Reddit and I agree with everything you just said. I don't know how to fix the issue, but I have some ideas.

One would be a "mod action audit." Each subreddit, or perhaps each moderator, would have a score indicating what % of comments are removed. Some random chunk of the removed content could be reviewed by auditors to determine what % were just spam and what came from legitimate users.

This way when I see a community where >50% of content is removed, I know that what I'm seeing is not organic.