Most content doesn't require that much healing unless people are just simply not paying attention to mechanics or any sort of avoidable damage. Sitting and raising people who die because of it makes you as a healer, a sitting duck for about 7-8 seconds. I only have so many ocgds to keep a party alive, and hardcasting Cure2/Adlo/Benefic 2 on someone that will just instantly die again to the next mechanic makes me want to prioritize the people that are actually staying alive.
Speaking of, my alt just got out of a Rabanasty raid where not only was the dps low and I started to see mechanics that I haven't seen in a long while, people were dying to avoidable damage left and right, including some people in my own party. It wasn't fun.