Ignoring the fact that a SCH who does that is susceptible to the inactivity penalty and getting automatically removed, any party who willingly allows that to happen is just as much to blame as the healer who did it in the first place. We have the option to vote players out for a reason. While the healer in your example is obviously lazy, I'd say the problem there lies with people who allow SCH to get away with that kind of nonsense in the first place. But we're talking healers in general. Can they DPS? Sure. Is it useful? I think that goes without saying. Is it a requirement that they DPS? Not at all.