Is "bad" a valid style of play?

A reader alerted me to a humorous post on the US WoW forums, where a warlock claims that "bad" is a valid style of play. He says:

I play a warlock. I, and many other warlocks, have been wanting green fire since vanilla. Maybe since before the game came out, we wanted to be wizards who could throw green fireballs. Now, finally, we have Fel Flame, and it is green. So the way I want to play is to only use Fel Flame, and to shoot green fireballs like a machine gun until things catch on green fire and green burn to death, screaming. I think Fel Flame is lots of fun.

But Blizzard says I'm not supposed to shoot green machine gun fire; there is a "rotation," which is a special order I am supposed to push buttons in, or else I am "bad" and the group I am in will "fail." Why is this the right order to push the buttons? Nobody knows. I feel like I am playing "Simon."

Anyway, in the last expansion, there was a different order I was supposed to push the buttons in. In the last expansion, the bad affliction warlocks liked to cast Soul Fire. In this expansion, the bad affliction warlocks are the ones who don't like to cast Soul Fire. How am I supposed to keep up with this? I heard about this site for jerks I am supposed to go to, but I am not going to do that. I am pretty sure it is a keylogger.

Now I'm pretty sure that most of you believe that "bad" is *not* a valid style of play. Which is curious, given the heated discussion about social responsibility. The warlock who doesn't feel a responsibility to play "good" is using exactly the same arguments as the DPS who don't feel a responsibility to switch roles: His way is more fun, and the other guys are just a bunch of anonymous strangers.

So where exactly is the difference? Why would 4 people who are absolute anonymous strangers to you, and to whom you don't feel any responsibility nor goodwill suddenly oblige you to play good just because the Dungeon Finder randomly grouped you with them? Imagine a dungeon that needs about 15k of total DPS: Why would three DPS each feel a responsibility to do at least 5k damage per second each? If our warlock does only 2k, another player does 5k, and a third 8k, the overall result is the same. And our warlock wouldn't be penalized at all, he could still roll need on all items he wants as much as the 8k guy, and will get the same amount of justice points.

But instinctively we feel that would be wrong. We'd call it "leeching" or something similar. Suddenly World of Warcraft is a team sport, and we feel a social responsibility to those 4 anonymous strangers. Why is that so? And why is there such a sharp division line, where we have a strong respnsibility to random players who are grouped with us, but not to the same players when we are not in a random group with them?