You really have to take a good look at your critical thinking skills if you see an immortal man sacrificing his defenceless young grandson's life (greater good or not) and interpret it as a depiction of chisel-jawed bravery.
absurd victory of Captain Jack
Captain Jack defeated the alien threat, but not until he'd lost Torchwood, his lover, his self respect and
his own grandson.
You call that a
victory?
He scraped through the ordeal and ended up with nothing. Not even the love of his daughter. That's kinda why he pissed off at the end. It wasn't a victory for him any more than The Battle of the Somme was for Britain.
Neglecting the contrast between Jack's success (aka victory) versus Gwen and Reece's failure, Bridget's failure, Lois' failure, Frobisher's failure and Ianto's failure means you're not even making the slightest effort to look objectively at what the story
is. They failed, not Jack. A suffering hero is not defeated, he's suffering. There are lots of people who think winning is the only thing.
It wasn't even Jack's plan, but Dekker's. The only reason Dekker and that woman didn't carry out Dekker's plan on their own, is because it's Torchwood the series, and Jack Harkness is the hero. He's supposed to be the one who steps up to the plate. The point of the story killing off Jack's grandson was not to portray him in a dubious light: Killing off one of the guard's children would have made that point even more obviously, making him like one of the officials who were going to sacrifice someone else's children. The falseness of writing that none of the guards brought their children to safety, so that it would have to be Jack's grandson alone shows that the point was to make Jack suffer.
Also, Jack, after decades and decades and decades of lovers was shown to reciprocate Ianto's feelings. In fictional context, an immortal couldn't invest into a love affair the way the youngster does. But showing Ianto as loving Jack more would in fact put Jack into an unflattering light.
Jack's moral villainy was already showed when he refused to resist their plans by releasing the tapes of the meetings. The show quite carefully skated over his motivation for this with some lame dialogue. The plausible reason, his grandson, was not alluded to precisely because the show did not intend to paint Jack as immoral or bad in any ordinary way. His immorality was arranged by contrived plotting to be successful at defeating the primary villains; at personal sacrifice, unlike the secondary villains, and, most of all,
necessary, right down to the choice of victim.
Of course, a lot of this was already explained, if not perfectly obvious on viewing. Ignoring it is falsifying the story. Rudeness is no substitute for a sound argument. It does serve well in place of an honest one.
If you thought that the point of that scene was that Jack was "brave" to sacrifice his grandson, then you, once again, just didn't get it, and have resorted to making stuff up about it in order to shoehorn it into your political ideology.
You're not supposed to come away from that scene thinking that Jack is brave or more admirable than the other characters. You're supposed to come away form that scene sick to your stomach and wondering if Jack even is a decent guy.
Missing the points mentioned above means
you just didn't get it. You're the one whose political ideology is blinding you to the obvious. For the very least thing, if Jack had refused to sacrifice his grandson, and Ianto's niece and nephew and all the other children had been transported away, who would think Jack was brave or more admirable, and have no question if even is a decent guy? Jack was very much meant to contrast with the Greens. Winning, instead of losing like Frobisher, was also meant to contrast.
The fundamental dishonesty is pretending that such far fetched dilemmas reflect something about real life, so that Jack's decision is somehow seen as tragedy. Such nonsense may resonate with your personal political ideology, obviously. But critiquing the ideological assumptions is any viewer's privilege. Making stuff up to counter the critique is not.