I have not yet got this far into the game, so I can't comment on the difficulty of this fight.
What I can comment on is some of the troubles people are having. Some of this may be stating the obvious, but not all of us are seasoned mmo players. This is my first mmo and while I have picked up the learning curve quickly, other may not have. Instead of berating them, why not try and help them out?
One big problem I am reading is that people are using the wrong companion. Sentinels, you need to be using T7. You are too squishy to be using Kira. You will far outdamage her turning the bosses hate on you and then you wipe. This problem seems to mainly only occur with sentinels, meaning I haven't seen too many guardians say that they used T7. Perhaps this is from tanks having a better understanding of the aggro mechanic.
What I have seen Guardians doing wrong is that they are not truly tanking. Kira should have guard on her all the time. If she does not have guard on her, she WILL pull aggro off of you and she will die. You do not deal out enough damage to take this fight on your own. Guard her always and use taunt to keep him on you at all times. Let Kira do what she does which is beat the hell out of things w/ that double bladed saber.
Lastly, what others have been saying, interrupt is your best friend in any fight. By this level, you should have three interrupts which is more than enough to prevent him from ever getting anything too crazy off on you.
Hope this helps!