Healers DPSing is part of the system. Due to how damage goes out in this game during trials and raids, if healers don't dps at all, they'll spend most of the time just standing around. Enemy damage comes out in bursts, especially when everyone is handling mechanics correctly. And healing health to full only takes a few button presses, its not like other games where healing is a constant uphill battle. So when you aren't healing, you DPS.
If you feel that you gotta be healing 100% of the time, either you or someone in your party is doing something wrong.
