Yea..... I'm sure it has nothing to do with the fact that depending on your class choice PVP is either idiotically simple or infuriatingly difficult to succeed in. I used to play tons of PVP through Vanilla, TBC, and Wrath - and as the Melee classes continued to become more powerful and caster classes felt more and more tied down to standing still and easily interruptible cast-time abilities, PvP became less enjoyable. Now that I have 110s of almost ever class, there are characters (and even specs of those characters) that I love to PVP on and those I can't stand to PVP on - and it has nothing to do with the players having "more skill, health, mobility," etc as you state - it has everything to do with the glaring imbalance between the in-game power of melee classes and the in-game power of most ranged specs - coupled with Blizzard's seeming inability to find a good balance for Healers in PVP that isn't either extreme of them being unkillable gods or laughable free kills.
No - it's not player skill or health that makes me avoid PVP - it's the fact that the PVP experience / skill cap / difficulty level from one class and/or spec to another is completely appallingly bad.