Originally Posted by
[-Spiritus-]
I don't have any numbers that can prove which playstyle has greater throughput, however, in the end it is irrelevant.
Having 1 healer spam shields of at least moderate value on the raid, every raid wide hit, is worth far, far more than any increased raw throughput that can be provided via healing in most circumstances. What it does is essentially "under-tune" the encounter because of the actions of one player pressing one button repeatedly.
For example, the developers say [numbers made up for demonstrative purposes]: "OK, here is the challenge. non-tanks have 100k health. We are going to have a boss ability that drops everyone for 40k, which at current gear levels will leave them at about 60k. Two seconds later, three random, unidentified people will get hit for 70k, effectively killing them without healing. The challenge is for the raid healers to heal everyone in the raid for 10,001hp in two seconds or risk a death."
Enter the bubblebot who has 35seconds to prepare for this mechanic. He places a 20k shield on everyone in the raid. Now, instead of everyone dropping for 40k, they only drop for 20k, meaning they are sitting at 80k health. Two seconds later, the three random people get hit for 70k, but instead of killing them, drops them to 10k. The broad healing challenge, "heal everyone up 10,001hp in 2sec," has been circumvented by one player spamming one spell. "Spamming" [due to out of control sustainability inflation via poor tier planning with the introduction of "hard mode" loot in Ulduar], in general, was such an issue in ICC that they had to design nearly all incounters around the idea that all healers would spam their highest HPS spell, which included Disc priests spamming their bubbles. The LK's Infest mechanic, in fact, was specifically introduced to challenge the bubblebot. "You must have shields on all raiders before X happens or someone gets Y." Anyone who attempted to heal infest [on heroic mode especially, when the content was relevant] without a Disc priest can attest to how gruesome it is.
Now, is it possible for a Holy priest playing "normally" to have a higher raw HPS by using all his or her spells? Sure. However, spamming bubbles can completely unbalance an encounter, removing the need to even worry about a key component that had been a part of the challenge in the intended design.
Getting back to the example, the developers say: "Spamming bubbles just broke that mechanic. Well, we have three options. (1) We can increase the damage of either boss ability by 20k to compensate for shield spam so the original challenge is intact and make the assumption that every guild will bring a bubblebot to the raid [The WotLK Model]. (2) We can limit the viability of preshielding the entire raid by either redesigning[pre-alpha Cataclysm model] or nerfing Disc [4.0.6 hotfix model]. (3) Or, we can design the vast majority of encounters so that shield spamming cannot affect intended design [i.e.- all fights like Chimaeron]."
So, in short, it isn't that Disc HPS was too high, Holy specifically shouldn't be spamming bubbles, or a poster of your liking or disliking says this or that. The point is that the ability to pre-shield an entire raid, regardless of spec, [or, essentially boost the EH of the entire raid] for every raid wide hit completely changes the dynamic of a designer's encounter. In a world where bubblebots are viable, he must either design encounters that are either (1) easier than intended with a bubblebot in the raid or (2) more difficult than intended without a bubblebot in the raid.