Avarage Thief's damage (lvl 80)?
Extremely low power it looks like, as well as relatively low crit chance. Lack of any points into the Power trait line is another reason. Another big part of high crits is having high critical damage from gear. Check into upping all those and you’ll start seeing a lot higher hits.
I would say the average theif damage is around 124k seems to be what most thieves have
Seriously low on power-also check that you accesories are up to date
The trick, in PvE, is to have all berserker gear on everything. For me, I have Valkyrie stats (power, crit damage, vitality) on my armor with ruby orbs, and full berserker exotic accessories. In total, I have around 50% crit chance and 108 crit damage, doing, on average at lv 80, 5-7k heartseekers and 7-10k pistol whips.
It’s all about your gear, to be honest.