Well, as I've said in my article, everyone's here for the money, so reposting content from other sites is the easiest way to go for most Steemians. However, reposting contents has two negative sides - first, it brings no exclusivity to our platform (hence, there's no reason for Steem to be high in value), and second, it violates copyrights (making cash on other people's work is copyright infringement), hence making Steemit look even spammier.
The solution is simple - we shouldn't tolerate non original content. Then everyone, who is here only for the money will quickly fail, seeing their posts downvoted. Steemit will be better off as an original content platform and content creators' posts will be more visible (unlike now, among all the spam).