Correct, there are too many posters writing irrelevant posts (Including me). There should be a huge filter of some kind.
But I do think anyone can get succesful on Steemit if you persist, your posts are high quality, you invest enough (sadly) and are consistent.
I think everyone should be able to post as much content as they like, however I do think there could be a better way to organize the content and to make it searchable in a better way.