In short, the benefit far outweighs whatever detrimental troll behaviour that is happening out there. Report healers who are misusing the ability. Even if you feel this futile, it still sends the message to the healer and everyone in the group.
Everyone's perspective is different. If you're a healer who uses the ability competently with good intentions then that's your purview; you only see what you do and not how Rescue is generally used by other healers.

I group with a variety of healers and from my perspective the bad FAR outweighs any perceived good. The ability is predominately either a tool for trolls, or used in ways that hurt more than help.

If you all don't want to change the ability mechanically then we should let people opt out of having it used on them. Add a toggle and leave it on by default, so people who don't want to be Rescued have to actively disable it.