@Lemons
I *did* acknowledge before that if a spec is coming in last in damage on a particular fight and the raid isn't killing a boss, then that spec might not be viable and needs the developers to improve it. However, if a spec is coming in last and the raid is still killing the boss, then how is that spec not viable? If the damage that spec is doing is still capable of contributing to the fight in a meaningful way, then how is it not viable.

Though I hate to use anecdotal evidence...my guild was stuck on normal Cho'gall for the longest time; and I had been asked to respec to fire from arcane at the beginning of our raiding push this expansion because that's what all the websites and blogs were saying was THE BEST SPEC EVAR! All these weeks were were banging our heads against the wall I was coming in last in the dps slots, even sometimes coming in behind the tanks. One week I decide to respec to arcane, because if I might get kicked out of this raid slot I'll do it having fun. That week we killed Cho'gall, and I was either second or third in dps every fight in the instance (with no other changes in our raid comp or changes in actual players and characters participating). So yeah, as far as optimization goes, YMMV.