A lot of healers tend to avoid using their full kit. People in the group or raid might be dead or dying while the healers cool downs aren't being fully utilized; lustrate, benediction, tetragammaton.
Perhaps focusing on DPSing too much has caused issue with utilizing the full toolkit due to focus being divided too much. It's possible, even plausible, that this is why Square Enix decided to remove some of the healer DPS abilities and focus the healers on doing their real job.