I think Jack Harkness is a fascinating character who's been derailed by the writers continually piling on more angst without addressing any of his previous angst.

- When intro'ed in Doctor Who, he was a former secret agent-ish type from the future with trust and honesty issues that were implied to extend from the traumatic and likely shady tampering with his memory by the organization he was a part of, and the ensuing identity/betrayal issues.
- Then he reappears in Torchwood, where he still has identity and betrayal issues, this time ensuing from his abandonment by the Doctor and the little miseries that come with being immortal. All acceptable and even plausible developments, except that TW!Jack is immediately established as being perfectly okay with wiping people's memories, a reversal that was never explained. (The creators involved later admitted they'd completely forgotten about his missing two years. Well, that's understandable; after all, it was only the basis for the primary conflicts of the character in Doctor Who!)
- We later learn that he was coerced into joining Torchwood and has spent the ensuing hundred-plus years as, more or less, an indentured lackey to an organization which disagrees with his most profound beliefs.
- Plus he felt responsible for the disappearance and probable violent death of his little brother as well as the disintegration of his family after said disappearance.
- Then he showed up again in Doctor Who and not only got his trauma thrown back in his face by the Doctor, but he was tortured for a year by a genocidal psychopath. After which the Doctor, onscreen, cried for said madman, but not for him. He returns to Torchwood and everyone's mad at him (not unjustifiably) without having a clue what he went through.
- Shortly afterwards, two of his coworkers and closest friends are murdered by his long-lost brother who hates him working with his former partner. He can't help his friends because he was buried alive for two thousand years and didn't get out until it was too late.
- His dear friend Rose returns from the parallel universe and, judging by the pacing of the last few scenes, gets dumped back there before they can catch up.
- He's never shown to deal with the aftermath of being BURIED ALIVE FOR TWO THOUSAND YEARS, or even the repercussions of seeing Rose (instrumental in his redemption from con man, and also for making him immortal!) again.
- Instead, he watches his lover die in front of his eyes and has to murder his own grandson in front of his daughter to save the lives of other children. His daughter cuts off all contact.

Seriously, a couple of these would be fine -- three or four, even, if the ramifications of earlier traumas were dealt with somewhat before piling on more -- but this is just ridiculous. He's gone from being a campy but mysterious and obviously troubled man learning to let himself be good again to an even wangstier Doctor with more guns and a convoluted backstory.