The people were caught as bandits a year ago. Right now, they haven’t actually hurt anyone in the village (the mage said that only the “thieves” are injured), and they tried to explain that they were doing their job. Most likely, they’re being employed as hired muscle by the local noble—the guy who has already been shown doing things that could incite a war on the border.
That’s probably also why the boy freaked out once he recognized Kane wearing the Duke’s coat of arms: he’s convinced that the nobles are behind the suffering in his village (and they may very well be).
And complaining about Kane is kinda pointless. His character is literally built around the notion that he’s the embodiment of kindness. That’s why he caught people’s attention in the first place, and that’s literally what enabled him to subdue and redeem a goddess of destruction. Don’t expect that to change any time soon.