And lets be honest here, Spike was useful in a fight, but he was far from a great fighter, he had just spent the last year running from fights, Spike specifically wasn't of use in the finale battle, had he not been there he could have been replaced by Angel, someone like Willow was a much bigger asset, as no one could have replaced her role.
Buffy was giving him credit as a better fighter and giving him a large leeway based on a emotions rather then thinking logically, what she was doing was reckless, this is the only reason I think Giles had no need to apologize.
Spike was at least a great enough fighter to kick the crap out of Angel only a few months later ("He beat me, Wes. He wanted it more") If there ever was anything that Spike wanted in the world, it was NOT to fail Buffy. He proved that in Season 5, when it would have been a whole lot easier, and way less painful, to have simply betrayed Buffy and her family. But he didn't. He could have just walked out of Buffy's house the next year with the excuse that "I'm just a soulless monster. Raping people is one of the things that I do." Or, he could have just permanently left town and only returned occasionally, because he was so attracted to her that he couldn't trust himself not to try it again, like Angel did. But he didn't do either of those things. Once more, he endured pain and torture to do the unspeakable, something that, as far as we know, was never done before. He regained his soul, in order to try and be the better man, the kind of man that Buffy could believe in, could trust, and maybe even love. Spike regained his soul, at a cost so great that it almost destroyed his mind. The killing, the taking of innocent lives, and whatever other despicable things that he had done, drove him into a basement, living in filth and feeding off of rats, just like Angel was when Whistler found him to tell him that Buffy needed him. Unlike Angel, Spike came out of his dark place with no prompting, as far as we know, from any outside source, for exactly the same reason. Buffy needed him. And she believed in him, trusted him, defended him, and she loved him. She wasn't giving him "credit" for being a great fighter, she KNEW that he was a great fighter. She knew from personal experience, something that no one else there had.
The decision to trust Spike based solely on her gut feelings and personal decision, in spite of what her friends told her is called making a command decision, something that commanders always do. She knew Spike far better than Giles ever could, and I'm not referring to the Biblical sense here. Her judgment in the matter was affected by her emotions and gut instincts, by her faith and trust. But that in no way implies that those feelings in any way clouded that judgment, and as we ultimately saw, those gut instincts proved to be more accurate than Giles' distrust or Wood's hatred.
The Amulet was intended to be worn by someone "with a soul, but more than human. As powerful a witch as Willow might be, she was still, at that time, purely and entirely human, nothing more.Of the others, Angel was sent away, for either the reasons that Buffy gave or something else.The point being, she didn't want him there for her final battle. That was another one of those command decisions, as was her right, as commander, to make.
And let's not forget that, while the Amulet had to be worn in the battle buy someone with a soul, but more than human, it also needed to be worn by an experienced fighter, something that none of the other girls, either before or after becoming activated, was, not by a long shot. Since she had already eliminated Faith from consideration, that left only Spike.
And as for running away from fights, we only saw him run away once, for what were, at that time, valid reasons. But, when the need arose, when Buffy was in danger, she got exactly what and who she needed to wear the Amulet. She got the Old Spike back. That was the Spike that Giles and Wood plotted to kill, despite Buffy's orders, both implied and specific. He was a good man, she trusted him, she believed in him. No room for discussion or doubt.
If Giles and Wood had succeeded, Spike would not have been there for the final battle. Without Spike and his sacrifice, the battle would have been lost. If the battle had been lost, the world would have been toast. No second front in the world, raised in a matter of a few days, could have changed that. Maybe that was knowledge gained after the fact, but it was knowledge gained, and based on that knowledge, yes, Giles AND Wood owed Buffy an apology. Hopefully, at some point between the end of Season 7 and the beginning of Season 8, those apologies were delivered, and in a most sincere and humble fashion.
