You are looking at it wrong. Your job is to be a teammember and focus on having an efficient team instead of saying "this is your job" or "this is my job".
To be efficient your first priority is to keep players alive. If those players are safe you can heal pets to keep raid dps as high as possible etc.
The other players should do the same and then this is not an issue anymore. When you start saying "only this is my job" then you suck just as much as the players with pets who assume you are going to heal their pets.