The reason we healers DPS

[Shurrikhan]

I prefer to focus on healing.

I dont DPS unless I know the tank can handle a few seconds without a heal or two.

I feel like there are far too many healers who want to DPS and neglect actually doing their real job as healers.

I far more often die because a healer refused to dps than because they refused to heal.

With my CDs, healing against a multi-pack pull can be sustained off oGCDs and HoTs/Eos alone for a significant duration.
But, once the CDs run out, no amount of GCD spam is going to keep me alive if no enemies have yet died.
By healing excessively, you denied us enough damage to survive the pull by denying kills before the CDs-covered period expires.
You, by not understanding the actual impact of your toolkit whilst clinging to a fanciful mandate of your "role", have killed me.