Okay.. I'll bite (it was my comment after all
)
Your right, you shouldn't be intentionally putting yourself in a party wipe situation, but it does happen. Not every person runs every quest perfectly -- and there are times when someone in the party accidentally or unknowingly pulls to many mobs at once. In those cases a well placed CC can mean the difference between many deaths (potential wipe) and a harmless mistake. When playing EE content, where mobs are hitting for an average of 160 per swing,with spikes that go much higher, there is no way concentration is going to cut it. With quicken you kick off the CC spell grab half of the mobs, giving the party time to deal with the situation.
So yes, if you always play perfectly, and everyone you play with doesn't ever make a mistake then you can likely run without quicken (excepting ToD). Personally, I know I am not that good, and I also play with a wide variety of players (many times PUG groups) on some of the hardest content. I know that quicken can save the quest if things go bad -- On the flip side, I can't think of a single time where having empower would do the same.
So, if you are playing easy content (ie anything below EE) or only playing with guild/channel groups -- Quicken is maybe not required -- but in those cases neither is empower.
If you are running EE content, and you want to be the person that saves the day once in a while -- then Quicken is the clear choice.