About the demonoid topics I would guess at a couple of reasons:
1) The newbie forum is more closely moderated than the rest
2) A matter of wording. You said you were selling invites, which is against their TOS while the other guy is giving away invites in response to a donation. It's practically the same thing, but the later could arguably be allowed.
Semantics, at the end of the day the final result is him making a profit and that is the definition of a sale which is against their TOS. What I did is none the better but leaving that thread open sends the wrong message to users. To say it is a matter of grammar chips away the validity of the action of closing my thread and the integrity of the admin who did it.