A few more episodes...
...a few more corpses. While the rest of the team might kill in self-defense, when you need a cold-blooded execution, Captain Jack's your man.
Ya know, Frank, I think I'm starting to share your dim view of Jack Harkness. Once you get past the novelty of gay sexuality in a sci-fi show, you start to realize that Captain Jack is just not a very nice person. Bit of a sociopath, in fact. Or maybe monster is a better word.
Am I getting close?