Im a bit suprised how it can be so difficult to understand. You can't expect Renderosity to make examples for every single thing. If you disagree with someones statement or something that Renderosity does, its doesn't necessarily mean that your view is negative, it depends on how you phrase your disagreement, if you phrase it through a personal attack on someone then its neither constructive or positive.

It should be fairly obvious that Renderosity wont encourage people to link to competitors sites, How many companies does that? Besides that and i might be wrong, but for instant if someone make a post asking for a specific item they once saw and its available on Daz3d or whatever and not Renderosity, I would be surprised to see that post get closed due to that, its not a secret that these other sites exist, but if someone make a post encouraging others to go shop elsewhere, like a commercial, of course Renderosity wont allow that and pretty sure the other sites wont like you doing that on there site either.