Are there many comic villains who *want* to die? I believe the Marvel villain the Machinesmith had that hang-up for a while, for similar reasons to Henshaw.
I don't think the Machinesmith had a hatred of all life, though. IIRC, for a while Ultron wanted to destroy ALL life on Earth; he was worried that in a few million years the animals and plants might evolve to become a threat to him.