Many reasons

1) Movement intensive. No good for fat and old fingers...
2) You will get Sapper, Onslaught, and drakes at the same time. At least twice in phase 1. Ship damage was my initial problem
3) Whole team following me is not viable, especially during phase 2. So have to change strategy and learn, and learn.
4) The transition to phase 2(positioning), the dodging of Goriona purple ground spell and boss aoe were tough to manage for me
5) zero armor means more than 300k hp lost from 2 quick boss hits, if you are unlucky. I chose 6 dps for faster kill
6) Aggro issue when onslaught and elites, just landed, came at the same time. They love my healers.

Lastly, my boxing skill is just so so....

Didn't want to share the video with failed attempts. But if you don't mind, the link is here. One mistake of mages break follow is enough to sink me.

http://www.youtube.com/watch?v=KGC1T...ature=youtu.be

High quality video is in processing