Atheists, the death penalty and abortion...

[catfish]

Not quite... It's an attempt at rationalizing the killing of the thing.
Perhaps you'd like to explore the definition of parasite? At what point does a human-parasite stop being a parasite?

Isn't that evident?
When it can function by it self, without the need for a host.

Then by your defininition, newborn children and comatose patients on lifesupport should also be considered parasites.