It's the easiest way to spread the word that ref spam isn't kosher. It's probably the sole reason that people who do post it, get called out and told it isn't acceptable by members.
To be 100% honest, I'd love those scammy posts to be available to public, behind a secured glass (with all links edited/removed, as well as all potential dangerous content).
But my post was also a (disguised) way to thank you for the work.