Kitru's right.
Homogenization is bad game design. The more your normalize performance, the more you get cookie-cutter classes with different skins and animations.
WAR being a "skill tank" with higher ultimate potential is perfectly okay - SO LONG AS there are still factors that keep PLD relevant at the top tiers of player skill. This is currently true (Spirits Within, Shield Bash, and Hallowed Ground immediately spring to mind) and content design will determine whether it remains true.
An MMO needs more approachable classes for people who either can't or don't want to push the limits. There's nothing wrong with them or ensuring that they can enjoy themselves. There also need to be rewards for the more skilled players, the trick is making the rewards real but not overwhelming.
The rift between average and skilled players already exists, has always existed, and will always exist. You can pretend it doesn't and try to homogenize it away, or accept that it does and give both groups something to fit their needs/wants.
It's virtually impossible to design a class, especially a tanking class, with a low skill floor and a high skill ceiling that is remotely balanced. If the gap is too large, then a skilled player trivializes content (it has to, for the low-floor end to be viable at all). The very players who could do so are the ones who want trivial content least.
We'll have to wait and see how 2.1 shakes out, but it is going to be a significantly happier place for WAR, the sky is almost certainly not going to fall on PLD, and so long as SE doesn't design around one class or another's unique strengths (e.g. intentionally write the need to Silence and Stun out of all boss fights + significantly remove the benefits of HG) both will have a useful place.