According to the survey, an equal number of people play the tank and healer roles

[HolyGlassofWater]

That isn't a population of what people actively play but what people have leveled. I also simply refuse to tank for a group of random people in the DF most of the time and I'm sure I'm not the only tank that does this.

You've missed the point. My posts acknowledges exactly this, my post is asking WHY tanks aren't queing in the DF. It's already a given they aren't