Say's who?
What if you decided not to wear a job stone at level 80? Or to use a lv1 weapon. Or to RP walk for immersion? Or play tank without stance because you want to be a dps Paladin. Or only use Vercure and Raise on RDM because you prefer to be support, or never touch a heal as healer because you want to be a Holy Mage and so on...
You'd be kicked immediately. But why? In all those examples you're just "playing however the heck you want"? None of those are strictly prohibited in the ToS, but you'd still be considered a griefer.
It's because it's an MMO. A social multiplayer game. A team activity. You aren't the only person involved or the center of the universe and your fun isn't weighted higher than 3-7 other players fun combined. So it's perfectly reasonable to expect a player to be trying to perform the basics of their class. Not perfection, just the basics. Aoe, your core abilities when you can, your heals and/or emnity and a minimum of gear. It's really not too much to ask.
Why is it like that though? You'd likely be booted or flamed immediately if you for example, went into lv80 content as a Conjurer even if you played well, yet a 0 dps healer contributes far less and half the community is absolutely fine with them.
