Originally Posted by
Keiyra
Beacon allows you to be healing both tanks at once (or another raider and 1 tank) - that's one very strong perk for pally tank healing. Also if you have to crank heals into your beacon target, you can do so and get a hefty cost reduction. Infusion of Light procs also make for some extremely strong single target heals.
That isn't to say other classes cant tank heal either, but holly pally has a fairly strong tank/cleave kit and since they aren't as good at raid healing, they often get considered one of the better tank healers.