The problem is that despite the game being an MMORPG which should have huge devides between low geared and high geared it's still a competitive game where skill should be the main factor. So even if you're maxed out in gear, guy who only raids occasionally can still beat you if he outdoes you. Forcing players to have good gear to raid but the only way to get good gear is to raid is a poor system so the game needs to be rewarding.
The problem is they give out good gear way to easily. You shouldn't be able to skip half the games end game raid content and go to the last couple of raid instances in a short amount of time once hitting 80. Also, to be in those top tier guilds you wont even make it through most app processes if you don't know how to play your character extremely well. People that buy accounts/gear or whatever are extremely easy to spot.
But yeah, there are plenty of actually skilled people that don't have the gear for whatever reason, but that is pretty much the whole point of WoW getting better gear. It is a shame most people that hit 80 now will never truly experience Naxx, it is Blizzards best raid content to date still. It was pronominal when it was originally released in vanilla WoW.
Giving out the gear just takes away so much of the challenge that it doesn't even make the game fun. Too many people have gear that is way way way above what their skill level would realistically get them.