So I tried to go for the the 'You don't belong in this world!' challenge and while I was in the Nellis Train Tunnel, I figure I might try and rack up a few points towards the challenge while I'm there, but when I killed them with one of the required weapons (Katana) they don't get counted for it. It seems weird that of all things, a Ghoul isn't counted as an 'abomination'. :/

cause human rights

SMs aren't treated as 'abomination' sither.

Ghouls have their own classification, Feral Ghoul. Abominations are typically creatures that have been manipulated through some means, like genetically or with FEV. They're not naturally created, they needed a human influence for their initial creation. That doesn't really apply to Ghouls, they're simply mutations caused by radiation.

Technically ghouls are just humans who have suffered a form of radiation poisoning. They shouldn't even be classified as mutations just diseased. The Karma bonus for killing the Feral Ghouls doesn't necessarily imply they're evil. Just that killing them was a mercy once they'd lost their minds. Putting them out of their misery so to speak.

Yeah, it seems Abomination is a classification for things that don't fit anywhere else. Why else would both Mr. House and aliens belong to it

I just assumed it was because of "reasons" for that to happen.