Ghostcrawler was a Jerk, But...
After dialoguing a little more, I've started to understand some of the frustration of healers in the Cataclysm era. It's not that the content is more difficult (though it is a part). It's not that people don't understand this difficulty and modify behavior to defeat it (though it too is a part). There's a large part of anger due to the arrogance and dismissiveness on Ghostcrawler's part, but that doesn't explain the backlash entire.
The problem is that Blizzard did not orchestrate this transition as well as they should've. LFD in Wrath required a very low threshold of communication and strategy due to the presence of extreme gear. It conditioned players to expect survival and victory, to view healers as subpar if they could not keep up with the fallout of ignoring mechanics and chain pulling. There needed to be some more exemplary work done to ease the transition to a mana conversation/ survival-focused (as opposed to survival-given) PuG style.
Hindsight is 20/20, but they could've done this using the pre-Cata events. It's a situation where you have a ton of players experiencing the same, new content. Why not explain the new mechanics using it? I'm imagining minibosses that can't just be healed through, adds that NEED to be CC'd to prevent a wipe. Extreme examples to illustrate a point: this is not Wrath. Cata is not what you're used to.
But personally, I put the brunt of the responsibility of individual players. Blizzard does not make players rude or judgmental; players do that to themselves. Given any threshold of communication or strategy, it is the players' duty to adjust with consideration for the other players. If the players as an aggregate gave grace and expected hurdles as we adjusted to the new system, no matter how jarring, it would've been a thousandfold smoother.
Ironically, here is where being a Calvinist becomes useful. Our nature is so depraved, I have no reason to expect such grace. This unpleasantness, at its root, is the result of human brokeness, partly on Blizzard's side, mostly on our side.