Basically because I get overwhelmed with ~feeeeeelings~ whenever I start about them, and then I wax lyrical about how they're the Naruto-and-Sasuke, Batman-and-Two-Face, Holmes-and-Moriarty of Homestuck. Except that it's better, because for Naruto-and-Sasuke and Batman-Two-Face it's sad that they're not on the same side and their friendship was lost, there's always a twinge of bitterness. Whereas the concept of kismessitude means that the break between Terezi and Vriska doesn't mean they wasted something, it means their becoming epic rivals/nemeses/girlfriends-on-opposite-sides fulfilled their potential.

And I'm afraid I'd do nothing but rehash canon events and gesture wildly by writing 'SEE? SEE? HOW PERFECT ARE THEY SERIOUSLY' and drawing the purple prose equivalent of sparkly spades all around them.

Wow, this post is a great example of why I didn't put them in first place. ^^

(Fef<3<Eri is yiiisssssssss. I ship Fef<3<Eri<3<Sol<3Fef too, but I thought that was a bit too much of a rare ship to stand a chance to sail. Fef<3<Eri isn't confirmed yet, and the OT3 version isn't even on the list, so I guess that was a good decision.)