He should of at least gave some of the organization members a chance and tried to make em see that they were doing wrong like Demyx probably could've gotten a heart if he worked with Sora on the good side somehow but Sora was mean and made fun of him. Other deserved to die like Xaldin and Xigbar and Xemnas and especially Larxene. I don't think he was right in killing them right away just because they were part of the organization.