You may or may not know, but if you want to piss off Iapetes, argue with him about how arenas are killing WoW. It's great fun. I suggest avoiding my mistakes and think of some irrational arguments beforehand so you don't have to make them up on the run. And now for something completely different:
PvP is not responsible for PvE nerfs. But maybe we can blame PvP for PvE buffs! Aha, you didn't think of that one, did you?
As we all know, and by we I mean people other than me until I read this post by Rohan: Regen is out of control. This is clearly the fault of PvP, specifically arenas.
Here's the situation: In a BG combat favors those who operate well on a 1-2 minute cycle. These are called death knights. However arenas, well I have no clue, I'm a noob. Let's move on to the shoddy circumstantial evidence.
Since arenas came out, with the exception of a big Illumination nerf, casters have steadily gained regen. Spirit scaling with intellect, intellect giving some classes mana/5, enhancement getting activated regen, eventually glyphs came out to boost mage regen, ret and prot gained regen, holy even got divine plea, you get the picture. People have loads of regen these days. Why?
It's not for PvE. No? No. PvE doesn't actually need regen. Fights could instead have been tuned for lower burst and output, putting more emphasis on efficiency over time. This hasn't happened, instead damage outputs are insane, matched out by the regen of healers. Why make this mess? Arenas.
Arenas are different because they have a few classes who don't need regen gear. They just get it by their normal play: warriors and rogues using energy and rage. Take a caster-healer and a rogue-healer team and start shooting it out. The rogue has natural regen while the mage does not. Without regen on gear and talents, the rogue could outlast the mage. The mage is forced to burn the rogue soon or risk losing through attrition, except burst was mitigated by resilience. The only solution is to remove energy regen and force rogues to stop attacking to regain energy. Sorry, I mean give the mage a lot of regen. Replace mage with anyone who uses mana and don't forget that healers get swept up in this.
Here we are now: caster must by necessity regen as if they had energy or rage in order to balance arenas and healers ended up in this too. To balance it in PvE, Blizzard had to do something with that all that mana: spend it on spamming of max rank spells (remember when people downranked for efficiency?).
Now that that is finished, let's move on to the flaws:
I mostly ignored it, but holy paladin regen was nerfed during arenas, not buffed. Furthermore, the great regen gain for ret is most useful in PvE, in PvP judgements are more likely to be absorbed, stopping the mana gain. In addition the replenishment buff works best in high-intellect situations, such as fully buffed raids where there are no shamans running around purging everyone.
PvE burst damage was going up throughout the time of WoW, not in reaction to recent regen buffs (I have a weird sense of recent, to me 2.0 is recent).
Much of the regen is necessary for PvE as fights got longer and was being added long before arenas. Long fights favor regen.
What have we learned?
I don't like arenas, but unfortunately, they can't be accurately blamed for ruining WoW. Sadly, facts do not always support opinions or theories.
Does anyone else do this, make up arguments and then try to prove them wrong? It's very disheartening when the one you prove wrong is one you like.