There are a lot of bad people in the world who do bad things. A lot of them had sob stories and were scarred and abused growing up. That doesn't excuse mass murder or crimes. You're responsible for your own actions.
While I'm not necessarily anti-Sasuke (I don't mind him as a character), I think if you look at his crimes, he definitely should NOT be forgiven. Jail is the best option if it could actually hold him. But I don't see how you forgive him.
Going after Danzo because of his orders against the Uchiha clan? I can see the rationale in that. But going after every innocent person in Konoha means Sasuke has gone over the deep end. You saw it in his interactions with Kakashi and Sakura after the Danzo battle. Sasuke's completely lost any trace of sanity. He just needs an excuse to go after people an inflict pain. If he did go ahead and destroy Konoha, he'd find some other slight/insult and go after someone else to kill them.
Because this is a story, I'm sure Sasuke will be redeemed by the end of the story arc. But right now, he's acting like a certifiable lunatic. I'm no fan of the death penalty, but I'd rather eliminate Sasuke than have him target any more innocent people.
