As Lore said (and this thread has meted out), this particular AddOn has caused a real split-down-the-middle regarding the viewpoints of players. Essentially, though, I think too many people are concentrating on the Professor Putricide example that he used and not the actual point; the default game interface is, quite often, not sufficient when dealing with complex mechanics.
I think we can all come up with examples of where that was the case and I'm not going to point any out because I think it could derail the point again. But arguing that things like VuhDo or Grid should be used is off base because they're not part of the default interface. Put bluntly, people seem to be arguing that you can solve Blizzard's lack of functionality in-game by using other AddOns to compensate.
Lore is saying that you shouldn't have to do this at all. The Blizzard interface should be good enough without AddOns being needed.
Funnily enough, my most recent blog discusses AVR and its removal and, I admit, I come to the same general conclusion as Lore on a couple of points. It's not really the AddOn that's to blame, more the encounter design. However, I believe that boss mods in general are way too sophisticated and are now forcing Blizzard to complicate encounters to the point of silliness. People working on things like heroic Professor Putricide and heroic Arthas are not telling me that they're having fun - they're telling me that they're stressed out. The slightest error in judgement is causing wipes. They're not playing the game without their hand being held, they're absolutely dependent on the timers in their boss mod to do what they need to do, at the right time. That doesn't take "skill" and isn't "fun" for those I speak to about it - it's learning an encounter by brute force repetition and hoping you down it before your tries expire.
Unwavering Sentinel: Tales of a Protection Warrior Running Wild.