That's what the voting system is for though. If someone is abusing the system like getting fake upvotes then that's def. a problem but the spam system accounts for that. Otherwise if the highly upvoted content on /r/entrepreneur is a bunch of make money schemes then thats what the people subbed to that subreddit want and you should start/find a diff. subreddit closer to what you want.

Also, it's perfectly fine if other people post that content it's just not okay if you are the one who wrote it and posted it so it doesn't stop the content from being posted just WHO can post it.