I don't think this issue has ever been up for debate though? :/ I mean, in most (if not all) threads I've seen on this matter, players who are "in favor" of DPS-ing healers agree that a healer's first and foremost duty is to keep the party alive - this will obviously cut into DPS time if the rest of the party are having fun eating up every single hit dished out by mobs.

Usually the rage against heal-only healers stems from the fact that some healers insist on overhealing and keeping everyone topped off ALL the time, staying put when no damage is happening, and thus not contributing as much as they could.