I think you make good points except in this little part:

"There are rewards for winning, but more than anything players find the mechanics of the experience to be the ultimate incentive. Rather than focus on loot, gold, and points, mmo designers need to go back and see what makes the core experience fun rather than what carrots they can place at the end of the stick."

Currently a great majority of MMO players don't care about fun but about the carrots in the end of the stick. Heck, one of the games that suffers the most wiith this mentality is WAR.
The PvP there when it happens is a blast, really entertaining. However, in the vast majority of times the players prefer to attack empty keeps and BOs because it has bigger carrots. And this in a game where gear is not that important to the PvP (you need to obtain gear for the PvE and the fights against Fort Lords and Capital City encounters).

In my opinion what Collin Brennan is defending is that PvP needs to evolve beyond BGs and player combat. However many games already did that! Hell, he even mentioned them.
EVE, WAR, Darkfall and other games all have a PvP system where combat is only part of the picture. They all have different systems but did many things beyond tacking battlegrounds. They have fully fledged PvP systems (some of those games still need a lot of improvements like WAR and Darkfall though). The average MMO player is more interested in PvE than PvP.