Right on. In fact, that’s the kind of thinking that abused women often use. “Yes, he may be doing bad things, but he’s doing them because because he really loves me.”
Newsflash: Killing others for the sake of the woman you love is NOT a good thing. It does nothing to make the crime less despicable.
As for saying “It’s Spike, and he doesn’t care about anything outside his sphere of ‘who to care about vs who to kill,’” there’s a term for that kind of person. It’s called “sociopathic.”