Disagreed, select all rankings, pick some random log, look at the bottom of the damage numbers and you'll quickly find someone grossly underperforming far beyond what their death tally would suggest. Lo and behold, the very first log I pick and there's a RDM doing 1.2k DPS on Hashmal with 1 death. And yet, in the mean time, my co healer manages a 85-93 percentile dps score on O2S after we both got MPK'd during the jump+knockback. You're trying to defend the undefendable here.
Also, your savage comment is flat out wrong. Simply surviving isn't enough outside of maybe O1S (which I'm hoping was just an error of design and judgement). The real big issue is doing the mechanics whilst also doing enough DPS to actually clear the fight. O1S's is right at the top end of what I typically see in dungeons, O2S and beyond are arguably above that.
Res sickness doesn't cause enrages, underperforming does.