The more I think about it, the more I think that Carl's death may be VERY bad writing, and possibly the show's definitive shark jumping moment, even worse than Dumpstergate. Carl is arguably the audience surrogate, as we have watched him grow up in this world like a hatching from an egg, and he is the bridge between the old civilization and new. Furthermore, his relationship with Rick is what makes both of them great protagonists. Plenty of other characters have dead kids and families. Carol, Morgan, Abraham, etc. It was the fact that Rick still had a son and still had to raise that son that gave Rick both his moral compass and overall will to survive. I don't think Gracie or even Judith (who is not Ricks kid) can replace that, not convincingly at least.
So now Rick will be in the same boat of post-family brooding as Morgan and Carol, so his character will be less interesting and unique, and apparently this is all to give Rick a reason to spare Negan, which makes this death a terrible plot contrivance to allow another plot contrivance. The thing is, there are plenty of other characters who could have made this sacrifice. Morgan, Gabriel, and ESPECIALLY Daryl, whom, as I stated earlier, has absolutely no business outliving Carl.
And for Carl to get killed by a couple of walkers also depleted the sense that characters are adapting in this world, since the logistics of the walkers allows them to be either defenseless or deadly depending on plot convenience. This extends to Negan and The Saviors as well. Their ability to launch such a wide and destructive counter attack on all 3 settlements after Rick spent a half season attacking all of their other outposts makes the entire past season feel like a complete waste of bullets and time. And that doesn't include Eugene's magic ability to spawn bullets from his ass, which he must have done to give the Saviors ammo since they would have had to use all their original ammo to escape the Sanctuary.
All in all, I feel like the show may have finally crossed the Rubicon of quality that I don't care anymore. Without Carl, it's just a bunch of depressed people running around aimlessly. It feels like there has been a massive loss in stakes and story potential.