but there is a segment of the fandom that has no interest in that pairing
Like me! I've only ever read D/M when someone else was involved. For whatever reason those two don't do anything for me whatsoever. Mind you, I'm a crossover whore and I like my HL pairings in particular to reflect that.
See my icon? If there's any such thing as the OTP for me, that's it. Jack Harkness and Methos. yum. Strictly speaking in current Torchwood timelines it's OT3... can't forget about Ianto after all! *g* I've even written that.