Poe is smart, handsome, charming-how is he single? He isn't. Prior to the events in TFA he was seeing someone on base (gender unimportant). Having their boyfriend go MIA/presumed dead/captured/tortured/crash, then come back only to lead a borderline suicide mission against Starkiller and come back with less than half of the squad has kind of taken the sexiness out of dating a starpilot. Cue awkward, preferably public break-up.

Moping!Poe was half-expecting it, since it follows the same trajectories that most of his other relationships have taken.

Just after Poe angst, good buddy pilots helping him through (another) break up, and maybe some Finn(/Rey) profiting from someone else's loss.