Darkleer reasons which only Darkleers can understand.

But! Karkat is in the quadrants of his 'family' and Nepeta's... something, he doesn't know. So he can respect and value that, along with Karkat's position as leader of the younger generation even if he is extremely loud and uncouth, *gosh*.

He kind of vaguely faintly off in another universe likes Karkat! But not enough to try and approach him in any way whatsoever. Also he has a feeling the books would get thrown at his face, so yay anonymity.