Very belated welcome to LP!
I definitely agree... even though none of those characters had a speaking role, I imagine they did weigh on Jack's mind as some of the people "left behind" who needed to be saved. If they were killed for a reason, then at least have them be mentioned as part of the motive for Jack's plan to detonate "Jughead". Thanks for the message! I'm actually worried the "Forget the Details" method of Season 5 will continue in the final season...
It looks like you and I have something major in common....a concern about the Background Characters and the way they have been just tossed aside. I have posted the same concerns many times. I'm afraid it's just part of the Rushed, "Hurry Up And Get It Done, Forget The Details" Syndrome that has taken over on LOST.