Why do you think Blizzard never implements a 1v1 arena ranked by class/spec?
Of course some classes/specs are better than others at 1v1, but it would be incredibly easy for Blizzard to simply rank a 1v1 based on your class/spec (as in you are pitted against all random classes/specs, but you are only scored against how well others of the same class/spec do as you.)
Personally, I would love this and I think a lot of others would too, but I'm wondering why Blizzard has never implemented it. I'm thinking the reason is that they think from a psychological perspective that people will quit the game faster if they realize that they are not very good at PvP OR that it will alienate them from any sort of cooperative gameplay and hence quit the game sooner.
Because classes which can spec tank will dominate.
Yeah but even if the average tank wins...lets say 75% of their 1v1 and the average...let's say fire mage wins 25% of their duels, there would still be the tank that wins 95% of their duels and the fire mage that wins 50% of their duels. In other words, there would always be a way to differentiate yourself as being better than the others of your kind.