If you ship a rarepair why?
I'm genuinely curious! For mine it's because the other character's Canon love interest isn't developed at all. The main character is in a Canon pairing which I actually do like but they spend the majority of the last part alone due to circumstances and they and the other character end up leaning on each other for support. I honestly don't know why they weren't explored as a pairing together.
Edit: also what are they if you care to share because now I'm curious!