They extinguish far too quickly to be of any use at all. No one uses them there despite the fact that they ward off the grues since you can go through 5 or 6 inside 10 minutes. For people to actually begin using them the extinguishing of the torches can't happen so swiftly, they're nothing more than wasted gold.
They really do die very quickly. I enjoy the fact that all other sources of light get eaten by the stones, but torch light... I think that should be extra long since its a Hand slot and costs gold.