i don't think leaving trolls alone to spread their misleading nonsense without at least one response is such a good idea, specially when their comments are reported they aren't being removed by mods, or maybe they are in that grey area where you can't just brand them as trolls.
but at the same time feeding the trolls is not a good idea either. they have a way of sucking you into a long discussion without any conclusions.

maybe a balance must be reached, where you don't get sucked in while still not letting them mislead.