A Templar is the only class that has a skill line dedicated towards healing / shielding / buffing. Every class has access to a restoration staff. By definition a Templar will always come out the most healer oriented if that is their only focus.
Any class can keep a group alive with a resto staff. However, if you're ever grouped with anyone doing stamina DPS, a Templar is absolutely vital. Blazing Spear and Repentance are excellent stamina return skills that make an enormous improvement in sustain. Templars also have the best emergency heal with Breath of life.
Also, don't knock templar DPS, they're capable of a whole lot more than most assume.