I think you hit the nail on the head. Many of the comments on the net blame one group of players or another (bad tanks, lousy DPS, etc.), but the truth is that the Blizzard devs bear the brunt of the responsibility.

By allowing players 1 full year of over-powered steamrolling of heroic Wrath content, they conditioned the player base to the notion of quick, easy dungeons runs for badges. Then they turned the tables by simultaneously making tanking and healing "more interesting", and at the same time tuning the dungeons to require near raid levels of player cooperation. The idea that these factors would greatly increase queues in the LFD system for DPS shouldn't have been any surprise to them.

The truth is, Blizzard devs are now trying to bandage the system to keep the player base happy. No reasonable amount of bribery will takes queue times anywhere near back to what they were in WotLK (unreasonable bribes would of course blow up in their face even quicker). If WoW keeps bleeding casual players (whether they leave to go play Rift, and later SWTOR, or just leave MMOs altogether), I predict that Blizzard will be forced to forgo their design aspirations and swing the pendulum back to casual/easy tanking and healing in the next 6 months.