Newer content isn't being made with the same difficulty curves as content was back in the day. The days of sub-i90 gear (assuming Darklight-ish) trying to kill Titan just to START your relic were more difficult at the time compared to today's Soldiery-based i110 parties trying to go through things like Final Coil.
Back then you almost had no room to do anything but heal. Nowadays people are finding the gaps when everyone can squeeze out more damage to speed up the content, so it's turning into an unwritten expectation for many people.

First priority is always heal. A living DPS damage and pure heals > dead DPS and healer damage any day. Just don't be afraid to try to sneak in a few Aero's here and there.