Am I using the targeting system wrong or what?

[Billzey]

There is a much easier way to target enemies that are currently aggro'd, especially useful for raids. Most people just see the Enemy List as a way to determine if you have aggro on mobs, but it's actually the most effective targeting utility in the game. Drag the Enemy List near your hotbars, or wherever is most convenient, and simply click on the name of the enemy you would like to target. This targeting method will work even if you cannot currently see the enemy, and it is impossible to mistarget unless you are horrible at clicking the mouse.

The only time this method does not work well is if you are fighting multiple mobs with the same name. It does, however, display the remaining HP of the mobs, so you can use that determine which mob to target.

[Souljacker]

The only time this method does not work well is if you are fighting multiple mobs with the same name.

Any solution that involves "clicking" is not an optimal one. Tab targeting is the chosen method for the experienced tank, a tried-and-true method to cycling your abilities around evenly. Targeting just needs to make sense, and in this game it doesn't. I don't know who thought it was a good idea to target the furthest enemy away first even when you drill down all the filters to ONLY target aggoing enemies...
But that's SE for you.