I agree, as far as Class Tuning is concerned they do the buffs and nerfs for PvE and PvP separately already. Unfortuantely overall class design (utility and mobility and the like) are all intrinsically based around PvE which makes it all wonky in PvP.
The issues with PvP go so much deeper than just Class Tuning which is quite literally the only Blizz touches and they screw it up by leaps and bounds every single time.
This post does an incredible job of laying out how severe the situation actually is with the biggest issues being completely unrelated to Class Balance.