Yesterday I posted about series finales, and I wanted to talk more about AtS. I know a lot of people dislike "Not Fade Away" because it's a cliffhanger, or because of some of the things Angel did, but that's not the problem I have with it.
From a metaphorical perspective, I think the ending is incredibly fitting, and in comparison with "Chosen," it perfectly illustrates the difference between BtVS and AtS. BtVS was about winning, about defeating evil, and so it ends with a triumph over the First, the closing of the Hellmouth, and (as always) the saving of the world. Whereas AtS is about fighting, the never-ending struggle to do good in a world where evil is the status quo, so it's appropriate that the show goes out, not with a victory, but with its heroes charging into battle. And I don't have a problem with Angel being wrong or morally flawed because, quite honestly, he's always been like that. I don't mind my heroes a little dark. I don't even mind the implication that everybody's going to die. I just want their deaths to be meaningful.
And that's the problem.
Much like Buffy's battle strategy in "Chosen," Angel's plan is really DUMB. What exactly does he hope to accomplish? He wants to take out the Black Thorn in order to make a statement, to "bring their gears to a grinding halt, even if it's just for a moment" - but what about the next moment? The moment after that? Who will fight for humanity when all our champions are dead in an alley? And that's what bothers me, because Angel chose this moment. He wasn't in immediate peril.* He wasn't forced to act. He could've continued his fight from the inside. And sure, he's worried that he's not really doing good by running Wolfram & Hart, worried about being corrupted by its influence, but at least he'd be continuing to fight. It's what he does, what he's always done - to borrow from Starbuck, "Fight 'em until we can't."
This power play is pointless. It ultimately accomplishes nothing. Wolfram & Hart will recover. The Black Thorn will be replaced, and no one will care that Angel stopped them for one moment when the next moment they're back in power. Angel is sacrificing himself and his friends for a fruitless symbolic gesture.
IMO, it only works if there's some bigger picture, if the Powers That Be intend to use this vacuum to seize power away from the Senior Partners, if they intend to use this moment to create a systemic, lasting change. There's some suggestion that this is, in fact, the plan, since Angel got this brilliant idea from Cordy's vision. The Powers That Be wanted Angel to do this (unless he got the message wrong). But we never get to see what that plan is.
(ETA) The other alternative, as discussed in the comments, is that we accept that Angel's made a wrong decision, but we give him the chance to redeem himself. He's lost hope, and I understand that, but the only way it's satisfying to me is if we get to see him built back up again, if we get to see him come out of the despair that led to this decision, rather than ending Angel's story when he's at his lowest point.
And there is the irony inherent in AtS' series finale. Because although metaphorically it's the perfect ending, and any sort of continuation mars the imagery of the fight that never ends, in other ways it only works if there's a continuation, if we see that there was a reason for doing this, that their sacrifices weren't in vain.
*Actually, I think it would've made a much better ending if there WAS an immediate threat. If Angel and all his people's lives were in danger, and the only choice was to get out of Wolfram & Hart, but they knew they'd probably die anyway trying to escape, and so they decided to take the Black Thorn down with them.