Not much I can do about my group "doing it wrong." I've been in guilds where mages have been appreciated for their glass-cannon-ness (usually when RL is/has been a mage), and guilds where mages are just an afterthought (ie: give storm crit buff to melee during Hodir). I'm in the latter. I'm not complaining, though. We get a lot done and still have a lot of fun, which are the two requirements for me for a guild. :) I actually mis-spoke, though, it's not that melee all get the bite first. What really happens is that a hunter usually gets it first, then the bites are spread into each group, at which time bites are distributed amongst the members of the group. The other mage and I end up bitten last or not at all because our group is bitten last and because we are "little," thus harder to target. :) It might happen at some point that the mages will be bitten first in order to make the fight go faster, but not right now, and we 1shot her last nite, so no biggie.
Looking at the logs last nite, though, I did beat a couple of people who got the bites. :)
To the OP: I'm still struggling with my dps on a few fights, but see how your dps improves with Incanter's Absorption. Also, at the beginning of ICC it was kind of like at the beginning of Wrath, where a lot of mages were scratching their heads about their dps, but getting more gear helped a ton. As you get used to the fights and your gear gets better, you should do better.
I don't envy you, though. I don't like to be ridden about my dps, since I am constantly reading EJ/using Rawr/trying my best. If I were on the bottom of the charts, that'd be one thing, but if I'm pulling my weight and we're killing things, it's an insult to me for someone to ride me, as if I am not doing my best and researching my class constantly.
Personally, if I were being targeted like that, I'd be demanding all BiS drops! lol not really, I just don't think it's fair to demand that a player do the same dps as another player with much better gears.
/rant