I thought Wood's reaction was very human. I think most people when confronted with the murderer of someone they loved wouldn't give a damn if that murderer found God or inner peace since then. And technically innocent doesn't really cover it. Soul or no soul it was still the same body. Spike still has the memories of doing it. But does he even feel the slightest twinge if not remorse but at least empathy? No. I thought that's what the soul was supposed to do, add conscience. If he can't even empathize with another beings pain then what is he using it for (other than the perfect card blanche with Buffy)?
Wood's reaction was normal and human, but it doesn't make it okay. Revenge is a normal emotion, but it's almost never right. Let's not compare Spike's soul, or any soul for that matter to God or inner peace, it's not even remotely the same. A soul is literally a conscience. Had Spike had a soul all along, he would have never killed Nikki, by itself that means he is innocent.
And about the remorse, Spike dealt with his soul differently than Angel or whoever else (I don't care who we use as an example and I couldn't care less about comparing the two, but the way Spike dealt with his soul is not necessarily wrong just because someone else dealt with it in a different way). I also never said that Spike wasn't a jerk. He was, and he was very insensitive towards Wood, but AtS s5 is the proof that Spike wasn't doing what he was doing just For Buffy. He actually did become good once he obtained his soul.
And I'd wager that that Spike still very much existed. After all he still saw nothing wrong with killing Nikki because he still thought that killing a slayer is part of some kind of dance. Well I guess it's a common way for sociopaths to think that killing isn't wrong. But to say that Nikki could have just quit...who with the what now? Since when can slayers quit. Death is the only way to 'quit' that job.
The vampire or the monster was still buried in Spike, but soulled Spike and un-soulled Spike were still two completely different man. Spike did have a point, vampires and slayers killing each other is in their nature, it is what they are made for, their purpose. Doesn't make him any less of a jerk for not being considerate, but Spike is not a sociopaths. If Spike thought that there was nothing wrong with killing, he would have kept killing. He wouldn't have chained himself in Buffy's basement. He wouldn't have offered to leave Sunnydale.
But yes, you're right, Nikki couldn't just quit. And Spike couldn't quit being a vampire. It's in their nature.
And how one can say that the monster who killed Nikki didn't exist anymore when he topped it all off with taking back Nikki's coat and wearing it again (aka the serial killer wearing the skin of his victim) totally escapes me. The coat being one of the trademarks of pre-soul Spike, a trophy of his killings. I fail to see the difference.
The difference is in his actions, not what he wears.
---------- Post added at 08:31 AM ---------- Previous post was at 08:24 AM ----------
And as a general comment, Spike should have been killed in s4, NOT s7. What they did in s7 was purely for their own agenda. Yes, it makes sense, yes I understand where they are coming from, but it wasn't about considering a higher purpose for killing Spike, it was about revenge and personal gain.
If they really wanted to make the right thing, they would have staked him as soon as he came back to Sunnydale in s4 or as soon as he got the chip.