but you make up for it with evasion, smoke bomb, stuns, blind, and vanish, so you don't take the damage in the first place.
Not to mention sprinting away w/ crippling is really useful in scenarios
For soloing vanish is useless, thats arguably one of the big problems, rogue solo survivability is pretty heavily built on the idea that rogues are slippery but in a solo situation quite often we really aren't. For instance the direhorns on the isle of giants, the triple puncture isn't dodgable, I can dodge every other melee swing but triple puncture will kill me unless I kill the direhorn first.
Recup and other new tools have extended rogue survivability but fundamentally rogues soloing still basically operate on rush down, pop your cds and kill the target before he kills you. You can say that is true of most classes broadly speaking but its much more pronounced as a rogue, if I screw something up I'm probably in trouble whereas on my monk if I do something stupid expel harm+chi wave can probably stabilize the situation.
Further I don't think, again comparing with my monk, that rogues do have many more tools to prevent damage. My monk can kite quite effectively with disable, roll and FSK, he can stun far more effectively then my rogue with leg sweep and FoF. He has paralysis for hard cc, diffuse magic for magic damage and ToK and Fortifying Brew for other damage.
I'm not going to say that the scenario the OP was talking about was hard but rogues do have a very weak soloing toolkit compared to other classes.