This formula doesn't originate from wow or any mmo, many many games completely revolve around getting better gear to do more damage/stay alive. Even countless single player games like skyrim, fallout, Diablo (online/offline), etc. Even the second legend of zelda game revolved around wasting time killing x amount of enemies to level up.
The deal is that in an mmo thats pay per month they want you to play for as long as possible because they have people who live off of making more content.
Its just a problem if you can only play twice a week, but thats how the cookie crumbles. You will get your gear eventually.