FormerlyHemlock
Hero
I can think of one reason for players to use it, though it wouldn't be a common situation. Namely, in your combat as war scenarios, that sounds like an excellent means of disrupting the industry of an enemy city. Evil, probably, but effective.
Sure, that would work. Another example is to use it as a Hiroshima spell: use it to end a war by proving strategic dominance in a way which leaves the enemy no choice but to comply with your terms. If used this way, it's probably a campaign-ender: if you end World War II, you probably just "won" the campaign and will have no further challenges comparable to the ones you just completed. (Unless you're playing Harry Turtledove's WWII, in which case you're winning the war just in time for lizard aliens from outer space to invade the planet.)
I don't expect any of these to be common scenarios, and even in these scenarios, Death Bringer is a way but far from the only way to triumph. (E.g. instead of wiping out a few city Hobgoblin cities, you could instead try a deep strike to kidnap the Hobgoblin emperor and top leadership.)
I think it's an interesting spell to have in a campaign.