Again though, this was their ticket to freedom, and the 100 refused them repeatedly. The leader's son was an asshole that forced the situation in the end, but only out of frustration. That's from what I remember, since it's been a while since I saw season 2. It's also just an opinion because I like the idea of moraly…

Its not black and white. That man lost his kids, his brother, everyone he knew because of Clarke. If that happened to you, and it was within your power to take revenge there is no way that the thought wouldn't cross your mind.