With no other changes, the time for dps to get into a group would not change significantly. probably a 5% change in time. The population of people grouping up wouldn’t be changing. you can attempt to make a case that more people would attempt to do dungeons because of the queue alone, but considering the time dungeons take, and the effort involved, i don’t think enough people would actually state “I only do dungeons because of the dungeon finder”
In a short period of time, there would be a small increase in tanks, for people wanting to try the class, but it would eventually level out back to what is now normal because the majority of people who would stick to a new tank class is going to be people who already tank. There has been no change to the true reason people don’t tank.
This is mostly a pointless question because it’s unique to every person. some people watch shows while waiting, some people have no patience, some people grind mobs.
None of this needs to be tested because your premise if flawed. If you had a different “better” reason to add dual spec, but as long as your reasoning is “But the tanks” its waste of time.
This is for the majority of people, strictly wrong.
Most people don’t want to tank, and most people Don’t like tanking.
If for some reason you are unaware of this, let me add some perspective.
Tanking brings a lot of stress to many players. If the group wipes, the tank is often held responsible. If threat is lost be the tank, the tank is often scolded. The tank is responsible for the group, the tank needs to know what targets to kill, and in what order, and thus needs to understand the whole dungeon ahead of time.
Even if these points are false, the sentiment still exists and that’s all that matters.
There’s more. Tanking is a dependent role. You generally don’t have a lot of personal ability as a tank. ie in dungeon, you have to trust your healer to survive. many dps have tools to kite, slow/ survive on their own, but its a tanks job to take the damage, and hope the healer heals, and hope the dps do damage.
Tanking is a (for the most part) a sacrificial role, and most people don’t wanna do that.