Expose function like taunt

Sysy

I found this weird mechanism in raid. When my toons got expose by the guard in phase 1, the guard will counter whoever has been exposed. I can understand that deathmarke functions like taunt. I can also understand that the pigs are smart to focus on exposed toons. But how can the guard counter attack the exposed? This is so unfair for Mace Windu. If you have to make expose as a de facto taunt when no real taunt is available, you should at least make it universal, not just in raids.