you don't understand pvp. It is not madness sorcs. If a madness sorcs dots are major help then the other team was going to lose horribly anyway. Madness sorcs are one of the best classes for dmg on the chart, however they are not anywhere near being a good competitive pvp class. Dots look good on charts, burst looks good for winning. People like you made sorc boring and made me a sad panda.
Know what you're talking about before telling someone they don't know what they're talking about. If a madness sorc is in an engagement, doting every target, bursting/deathmarking 3 and double doting two, every encounter now becomes unbalanced in favor of the burst fighters on the sorc's team.
Say a marauder pulls off to deal with this irrelevant class. Well, those DoTs are still up, anyway, and, assuming that marauder is not carnage (people like you don't know to roll Carnage, which benefits groups, instead of Annihilation, which gives 1 person a bunch of medals), he's been removed from the encounter (further benefiting the sorc's group) kited out and, since he's not smart enough to know to roll carnage, probably, ultimately killed.
Say a healer cleanses everyone. How many GCds has he now wasted when he otherwise would have been healing?