On the other hand, isn't it just a pet peeve for a handful of - admittedly vocal - players?

If a toggle is added, I think that there's a risk people will stop using it since they won't know if it'll even work or not in the heat of the moment. Furthermore, at present it can already only be used on people within one's own party - you can always seek out your own trusted healers to do content with who promise not to use the ability on you.