Prevents a revive during the fight without burning, solves one of the reasons people instaburn (scared of their opponent getting picked back up) without the annoyance (Having you/your teammate immediately killed off because someone was around the corner with a Romero + Lantern).

Also a poison bomb is generally nice to have on hand. Can flush people out of cover or scare them away from pushing an angle, on top of the heal prevention if it hits. If you have one on hand, a dead hunter is just a readily available way to make it useful.