"They want the rewards behind certain content, and don't want others to notice they didn't bother putting in what little effort it takes to perform at a level required to obtain it, instead having others carry them."
Unfortunately, that's how I see it, because people will abuse the hell out of a system where you can't be held accountable for performing horrible at your class. Not standing in the ouchies isn't very hard. Not standing in the ouchies while maintaining uptime, generally is.
I ask myself one simple question whenever I do content: would a group of exclusively me be capable of clearing this. If the answer is no, then I'll join a progress group, rather than a duty completion one.
I think you'll find that gaming is no different from performing a job - some people are naturally good at it, while others are not. Automatically assuming that anyone who's even remotely decent at something is no-lifing it, is incredibly short sighted. A lot of people will likely perform twice as well as you with less than half the time invested, just like you will be better at certain things IRL than they are in similar fashion.
Reminds me of the times where people called me a no-life PvP'er in WoW, while I had about 150 arena matches played to get 2800 rating and they had 750 matches played to get 2100 rating. Flawless logic.