The excuses are empty and hollow at this point.
If you can code a spell such as the one previously in my spell book (Curse of Doom) to not be castable on players, which was the way that spell worked from the time I began playing this game until Cata, you can make that same change or a variation thereof to ALL spells and attacks. Then there was a time when the "Blue" said that it would be too confusing to have that separation in the tooltips. Contradiction much? It didn't take long to figure out "I can't cast this spell on a player" back in Burning Crusade it sure as heck wouldn't take long to figure out "if I cast this spell on a player it's going to do X damage compare to Y damage from casting it on an NPC and even if you do get the headscratcher, reading the tooltip will enlighten you".
Draught of War: can only be used in Non-Rated BG's. Hmm you managed to code that but you can't do the rest of the job?
Excuses = old and tired. You said Cata would fix it, the health pool increase meant virtually nothing at all, I could be at around 50k health from the scaling of WOTLK to now and it would've been the same difference as having 150k and getting globalled or 2globalled.
If you're going to scale damage and health pools and not scale them correctly then the only real solution is to inversely scale damage in a PVP environment. If we're balanced around killing an NPC with 80m health as a group and individually able to do 30-50k dps, just HOW do you expect that not to be virtually the same in PVP? Resilience is nearly useless when the capability of damage output is virtually the same as me not wearing any armor at all. Resilience as a stat was a great idea but the implementation is absolute crap, then having it DR as it scales is just horribly stupid, it should scale even better the more you get or what's the point? Besides you're going to hit a cap eventually due to only having a given number of seasons in an expansion. I can only realistically add X amount more of resilience via gemming, otherwise it's capped with the highest tier of gear.
Now you're trying to take the Star Wars route and add "Power" to MOP PVP like SW uses Expertise. I'm still not sold, while it sounds like a good idea it really sounds like resilience reskinned unless you actually do something relative to how damage affects players vs. how it affects NPCs. All of this could've been done going into Cata, but no. Now all of it could be done going into MOP, but again, no, we're going to try to 'fix it' by adding yet another stat.
The simple solution is: code it correctly. You cannot enter this instance in PVP gear; You cannot queue for this BG/RBG/Arena in PVE gear. Then, you provide a starter set for each at a fair cost to alleviate the barrier to entry. PVE'ers that quest 85-90 get their quest rewards but have some options at cap to maybe fill out to all blues of an ILVL just shy of the level 5m's will grant and then your tiering is fixed. PVPer's do the same except that they get a starter set for JP or Honor or a combination thereof and maybe even a modest price of gold to start, then they go off and do their PVP'ng and get their first tier of gear for that season. Then you also have the craftables as options. You do that and make at least some separation on the way spells affect NPC/Player and you've come as close to balance as you possible can.
When balance is a lil whacky, you adjust either the player affected damage or NPC affected damage and wala, now a class isn't nerfed into uselessness in both forms of content and balance can be tuned much more easily rather than picking some talent that inadvertantly affects a class in PVE for PVP or vice versa. The ability is already there as evidenced by my toon alone and the way certain spells interacted with the environment from the Burning Crusade era. Excuses at this point only show laziness, disdain for one aspect of the game over another or just ineptitude, or a combination thereof.