Socialism

Is attack on titan about justifying extermination of the homeless? Never watched the show, only saw bits and pieces,.

That's just the vibe I got from it.

Like the giants are basically zombies / animals / vermin and it's ok, even good, to attack and kill them whenever, no further provocation needed. They can't be reasoned with, they're not humans, they have negative value, it's evil not to kill them even.