Lazerlike42
(Anakin falls to the dark side because his feelings and emotions are never addressed, and in fact what everyone keeps telling him is that his feelings shouldn't or don't matter. Yoda essentialy tells him he's not allowed to have feelings at one point during the movie.
Obi-Wan does not kill Anakin out of feelings. He himself shows attachment, something forbidden to the Jedi. If the Jedi were all correct in their ways, then Obbi-Wan is in great error and commiting the very same "sin" as Anakin did insofar as that he had feelings and attachment.
He was wrong not to strike Anakin and make sure it was done, but he was wrong not only tactically but also insofar as that he made himself a hypocrite. If it were so that the Jedi paid more attention to the human (or Twi'lek or whatever) side of people, both Anakin and Obi-Wan would very likely have been able to keep their feelings in check (though if Anakin did, Obi-Wan would have had no oppurtunity to). The error is on the shoulders of the Jedi order, of whom Yoda is a key figure.)
you have to have self control and don't let your emotions control you like Anikan for episode 2 attack of the clones he killed all those sand people cuz he was angry if you go around doing that you will have guilt of doing something wrong but being a Jedi means no distrations like in the war if you make friends or have some body special at home you will get attack and then when they die you get sad and spend time morning over them so thats why Anikan turned to the darkside he was scared of losing his wife and he tried to save her and he kinda killed her and why he didn't become Jedi Master was because he wasn't fighting at full potencial if he had more patience he would be the Master of Jedis