Where is the line between "playing your way" and being a burden?

In the constant (supposed) conflict between casual and hardcore players, one argument that frequently comes up from the casual side is, "I play this game to have fun, so let me play it my way!" This reply is used in a wide variety of situations, from suggestions on how the casual could better contribute to the raid to base taunting by hardcore players who think that casuals are somehow inferior to them. The advent of raids that are easy enough that casuals can actually run them has brought these two groups together more frequently than they have ever been together before, so this kind of conflict has begun to arise more and more. Who has more ground to stand on in this debate?

One of the arguments I see frequently cited by those arguing that they are only playing there was is that WoW is "just a game." I have already addressed this argument in a previous post and found it to be untrue. WoW is more like a sport (at least in the group setting): people come together to cooperate towards some competitive goal (even in PvE, the raiders are still competing against the raid bosses) for the sake of recreation. When you look at it that way, it's easy to see why someone who wants to "play their way" could bring the whole team down and make it less fun for the other people to take WoW more seriously. After all, some people find fun in success and measure their success by whether or not that raid boss was downed, so a more casual player could easily make that more difficult if they aren't pulling their weight. In that case, the river flows both ways: casuals often accuse hardcores of ruining their fun by taking the game too seriously, but hardcores can just as easily lob the accusation that casuals ruin their fun by not taking the game seriously enough.

Who's right? We can't say; WoW is a game, and how one plays it is completely up to each individual player. No one has the right to say that one person "should" play one way or another, so it seems the only surefire solution would be for casuals and hardcores to not raid together. However, in the grand scheme of things, this would do nothing to resolve the underlying issues that cause this kind of conflict in the first place. If the real source of the conflict is the idea that one group is preventing the other from enjoying the game, then the only thing that can really resolve this kind of conflict is for both sides to be more accommodating of the other. As they say, treat others as you would like to be treated.