You can't hold Spike's actions pre-soul against him the same way you don't hold Angelus' against Angel.
Okay, so I would use that point too if I was trying to argue for Spike, however, the writers wrote Spike as very similar with a soul and without, and as a special vampire from the beginning, so if they're going to do that, then I can absolutely hold his actions without a soul against him. If Spike was as different with a soul and without as Angelus is to Angel, we wouldn't be having an argument about it. And this argument is only valid at all, if Spike doesn't get credit for any good he did without a soul. You can't have it both ways. We don't credit Angel with helping kill the Beast.