Rant on healers acting as a dps role

[AsuraFreya]

I feel that if the other healers isnt going to do their role i may as well just replace them with a dps whose going to output more damage.

[Lyrica_Ashtine]

I feel that if the other healers isnt going to do their role i may as well just replace them with a dps whose going to output more damage.

Because the healing output requirement isn't constant. One moment you can manage by spamming Cure/Benefic/Physic. The next moment you'll need both healers casting Cure II/Benefic II/Adloquium a couple of times in succession. While it IS possible to manage these moments on your own as well depending on the content - And solo healing is done left and right everywhere - Risks are involved:
Mistakes from a single healer are far more punishing
Incredibly MP straining. To an extend where your bard/machinist need to cater to your MP consumption that it's not worth solo healing

There's also the fact that one of the two healers is a scholar in most cases. While you may not notice straight away, but the fairy has quite some presence. One you'll notice it's missing the moment it's a ast/ast or whm/ast combo as opposed to ast/whm with a scholar.