As a healer, is it my job to DPS? A new perspective.

[Judge_Xero]

Thus you can accomplish your main goal (of keeping your squadmates healthy) by not only treating them when wounded but also by contributing to destroying the enemy in the first place.

Can I try to debunk this one?

In a far off galaxy you end up fighting a vicious Hydra and because the medic is helping to attack and shoot of it's heads off, then too many heads grow back causing the hydra to wipe out your team.
Therefore a team of 8 Healers that don't DPS beats all.