If u play a emd game hunter like myself then you would kno that if you kno how to use ur spec correctly then any and every hunter spec offers excellent DPS. i play a MM hunter my self and i always am wthin the top 5 DPS'ers. so you should learn to play each spec before bagging on them.
Question: How far have you actually raided with your hunter? Before making a claim that MM is equally viable I'd hope that you have played AT LEAST through BT/MH.
In a way you are right, I could see MM being strong DPS when played correctly. However, the difference is MM does not offer as much potential in increasing the rest of the raid's DPS. Trueshot Aura is useful, but a geared/well played BM or Survival hunter will increase raid damage exponentially. I believe I have some experience in the area as I have played a hunter in SWP content. (Still on the Twins, so I may not see this bow for a week or two :( assuming it drops, hehe)
I hate to break it to you, but any intelligent, end-game raid leader will ask you to please respec, with TBC MM is just not a viable raid spec. The funny part is it used to be the opposite pre-BC, MM was prefered over BM. Who knows, maybe MM will get a nice buff when WotLK comes out. :)