It's a symbiosis though. Power posters add content for fake points because there is moderation to keep spam, trash, flamewars (when strictly moderated) at bay so their posts are not lost in the noise.

If a subreddit for a class of products gets flooded with sale spam, low quality content, memes, it will push the users who create higher quality content away. The same for a subreddit about hobbies, if it's not curated to have a good intro FAQ and collection of guides for beginners, and good moderation that is empathetic but can enforce guidelines on questions that constantly pop up, it will push people away because of the noise.

Moderation on reddit is what can control the noise, with a low signal-to-noise ratio the power posters disappear.