There will always be more DPS than there will tanks or healers. Thats a symptom that all MMO's have. But, you shouldn't be "forced" to play a tank or healer due to the wait being unreasonably long. There are tanks on, I see them all the time. Problem is, there isn't enough incentive to call them into action. A little extra xp and money ONCE a day, isnt enough to solve the queue time issues. Blizzard solved theres, they added a goodie bag that at the least contained flasks, money and such, AND you got it every time you queued. Which made it more worthwhile to run dungeons. Giving it out once, isnt enough. People do it once then forget about it.