Rust, CSGO, and WOW is quite different from Runescape private servers so I personally wouldn't compare them.
Unfortunately, stolen/leeched work can bring you quite some money, some people are even ok with that. I'd personally call it "Damaging your Image". Before doing anything ask yourself if you want to be known as the guy who made a profit off of a stolen/leeched base. You'd just be losing respect at that point imo. Not only then but whenever you're trying to build something again you'll just be hearing all the shit from before.