1) Under technicality, if your choice of play means we can't complete the dungeon in 90 minutes of time because you are actively refusing to do your role, you are breaking the ToS yourself. "Expressions that attempt to unilaterally exclude someone from the game or content/community, etc" being the exact quote. By expressing through your refusal to play, if it ever caused the dungeon to be unclearable that is listed as prohibited. You're just lucky you're playing the least impacting dps.
2) On top of that, you don't play melee. I don't see why that's your example. Your only capped class is Dancer. You don't have to worry about positionals, but based on how you act, I get this feeling you don't dance either.
3) I don't know whether to be glad or not you're playing a dps instead of a tank or healer. At least when you're being dead weight since you admit to not wanting to play the least bit proper since you don't find it fun, as a dps people can just drag your corpse, but if you were a tank or healer at least something could get more clear as you'd get kicked so much more often.