Spike is being quite mean, but in my opinion it's well-deserved.

The fact that is Spike doesn't make it right. Spike is brought just to contrast Angel. How is he more entitled to yell at Buffy than all the other characters in S8? Why not Satsu or Xander or Giles? Oh, no, let's bring in the rude, jack-ass Spike. He's British, snarks a lot and he's wearing the coat! On top of it, for him Buffy transcended from "hell of a woman" to "hell of a ride"