Two reasons: first, because I don't feel like Orin is a shipping kind of gal. Kinda the wrong personality. And second because think it would be more fun to try to do Okuu x Cirno, though I haven't the faintest idea how I'm going to do that. :3
On another note, I'm thinking of trying out a name for the shared-universe as a whole; I feel like there's something vaguely awkward about calling the whole universe (fanfics, shorts, other comics, and all that) by the same name as the comic. I'm considering, for the Japanese name, 東方偉虚数/Touhou Erakyosuu, meaning Oriental Great Imaginary Number, on the basis that I've started going at right angles to canon (MATH JOKE!). For the English name I'm thinking of something involving "time paradox," given that the divergence from canon is, broadly speaking, caused by the Broken History bit.