I think we've all been there before. Someone posts in Trade "LFG, Firelands, PST iLvl/Spec". Honestly the most casual players are probably so far removed that they don't even understand that, but what about those that do? They'll send the reply, something like "365 Frost Mage". And they never get an answer back. Maybe they've had bad experience with a newby before, but odds are the reason that the Frost Mage didn't get an invite is because people have put in ridiculous requirements for Raiding.