I can live with Spike’s ending in a blaze of glory by focussing on how the show has severely problematized the whole idea of a ‘noble death.' It was one of the things I liked a lot about the way it continued after The Gift. Also Spike has always been a character of extremes, he can be hero guy and he can be “I didn’t give a piss about your mum” guy but the one can never excuse the other.

Spike wins, and at the point appears to still be fooling himself that killing those Slayers was winning some kind of honorable duel
Or the nature of things that you and selenak were discussing over on her journal. I think what the show is reaching for here (and throughout the season) is not that vampires killing Slayers is natural but rather a natural consequence of the ‘One Girl in all the World’ set up. Spike was Nikki’s murderer but if she had killed him she still would have likely died in some other battle accepted as part of the mission she could never share or take a break from. Spike, misogynistic and brutal while he might be, is not the patriarchy but its instrument. The bigger enemy is the system that gave one woman the non-choice between a short life filled with violence and letting the whole world go to hell.