WOTLK Potion Sickness: Frustrating

The latest bit of news to come from the WOTLK Beta is a new Debuff one gains upon consuming a potion:

Potion Sickness: Unable to consume potions until you rest out of combat for a short duration

This means that in any given fight one can only consume one potion. The crux of the problem is that, presently, in a 10 minute boss fight potions are the means by which healers replenish mana, casters replenish health and mana, and various classess buff themselves via potions. With Potion Sickness that ability is removed. Here are some of the Pros and Cons offered by the masses:
Pro:
- Minimizes emphasis on potion guzzling.
- Lessens the grind (herb farming, gold farming) presently required to amass potions.
- Places more emphasis on gear/spec.
Con:
- Makes alchemy less profitable.
- How will Raid Healers/DPS replenish their Mana/Health without mana/health potions on 10+ minute fights?
- Fuck change.

The Pro arguments can be met with the stance that the "problems" they raise are not actually problems; that this change is not needed. The Con arguments can be met by changing class mechanics to minimize the need for potions and by ignoring their being irritable. What I think is more interesting is to acknowledge both the Pro and Con arguments and ask the bigger question: Why change?

The problem I have with assessing World of Warcraft changes is that I do not know what the developer's end goal is or even if they have an end goal. Are they adding Potion Sickness to solve some problem or simply for the sake of change? What changed when Paladins and Shamans went from being faction specific to being available for both Horde and Alliance? Why were Warlocks able to summon players into instances, then not, then able once again? Is Blizzard constantly tweaking WoW in an attempt to actualize some desired perfect balance, or is there no such balance and they simply enjoy tweaking?

Is it problematic that casters can drink a Destruction Potion every two minutes? Well, I cannot answer that question because I do not know what "problematic" means to Blizzard. From my stance as a Warlock who consumes Destruction Potions every two minutes during a 10 minute boss fight? Yes, this change sucks a bit. But what of the situation from Blizzard's standpoint? That's the question I cannot answer, the question which needs to be answered to assess this change. Is it change for the sake of change, a balance issue, some striving towards another goal? Why make the change at all?

That's the frustrating part of this whole thing: We do not know what Blizzard is trying to do. So we can talk about how it personally affects our class, our group, our raid. But we cannot talk about how this affects the overall situation of WoW. Because, really, only Blizzard knows what that is.