Spike didn't choose love over the apocalypse, he grabbed Dru and ran, fully expecting Angelus to kill Buffy and procede. And S6's biggest drag was Buffy's complete loss of her previous spunky attitude, changing the tone of the series though Willow's character destruction wasn't far behind, damned stupid story executed poorly.
So the fact that his continued pressence ruined every other character makes him show saving?