In The Walking Dead Deluxe #84, Kirkman outlined the "original scrapped ending" that would have capped off the adventures of Rick, Carl, Michonne, Negan and Andrea. Describing his original idea as "bleak, sad, possibly terrible," Kirkman originally considered the ending set in stone, even telling it to The Walking Dead's executive producer Greg Nicotero and Rick Grimes actor Andrew Lincoln ahead of the show so they knew the final direction the franchise would take.
According to Kirkman, The Walking Dead was slated to end with a mislead, suggesting Rick had led humanity to re-establish a working society, only to then reveal the zombies had overrun it, finally wiping out the living. It's a dark ending that would have defined the franchise, and yet due to its success and longevity, Walking Dead won Kirkman round to a different conclusion.
Kirkman Intended the Zombies to Win
Thankfully, Delaying the Ending Changed His Mind
In his creator notes to Walking Dead Deluxe #84 - from Kirkman, Charlie Adlard and Dave McCaig - Kirkman lays out the intended ending.
So, the basic gist is that this massive zombie attack would have happened in Alexandria, Carl wouldn't have been shot, but everyone would have come together, as they did in this issue, and overcame the zombies. Rick's hopeful speech to Carl at the end of this issue would have instead been a rousing speech about hope for the future, and how they were going to put down roots in Alexandria and rebuild civilization there, etc. As the speech winded down, we end on a cool shot of Rick standing up in front of the crowd, then you'd turn the page and Rick would be in the same pose, but now he's a statue commemorating that speech. An indeterminate amount of time would have passed but the statue would've looked old and worn, and we'd start zooming away from the statue, as we got further and further away, we'd see that Alexandria was in ruins, long abandoned and the final image as we cut away, ending the series, was a zombie casually walking by.
The idea was that Alexandria was successful enough for Rick to live out his life there and have a statue erected in his honor, but ultimately... the city fell and the scourge of the zombie apocalypse just... continued on. So, we'd leave readers with the idea that no matter what people did... the zombies win. I know, right?
Thankfully for fans who had followed Rick's group for 193 issues over 16 years, Kirkman repeatedly put off this ending, reasoning that it was something he could do at any point in the story. Because it involved a jump forward in time and a wordless scene, Walking Dead's original ending had no expiration date - it didn't even require any specific characters to still be alive aside from Rick himself. This meant that as the series' readership continued to swell and Kirkman kept having new ideas for what could come next, the ending was pushed back, and back, and back, until the story reached a point where Kirkman no longer found his intended ending satisfying. He explains:
I didn't want to end the series; I was having too much fun. Please believe me when I say writing this series was a huge source of joy in my life. ... For a while, I just kept pushing this ending back. A speech that transitions to a statue of Rick? Eh... I could do that any time. But over time I, rightfully, realized it was just not a satisfying ending. Not after spending so much time with the characters, so I abandoned it altogether.
What's cool about the process Kirkman describes is that Walking Dead escaped its downer ending for the same reason that ending wouldn't have worked - readers had put too much time into these characters and their world for such a glib sign-off, and as the series continued to inspire its co-creator, he ended up in the same position. For fans of pop culture, it's really cool to know that Walking Dead essentially saved itself by being too good to end - and the intended ending would have hurt the story in a major way.
Walking Dead Deserved Better Than a Downer Ending
The Comic Goes Out on a Complex, Satisfying Note
The other reason that The Walking Dead was published in black and white was to get away with more gore and violence, 'toning down' extreme scenes without pulling any punches in terms of actual content.
In that context, killing everyone off and bringing all their efforts to nothing wouldn't just be dark, it would feel like the reader had wasted their time caring about all the twists and turns that ultimately came to the same ruined world that could have been assumed from the first issue. Instead, The Walking Dead #193 serves up a complex, compelling vision of this world's future. Jumping ahead 25 years after Rick Grimes' murder, fans get to see what has become of both humanity and the comic's many surviving characters.
Walking Dead's ending sets up so many ideas, Kirkman has hinted that the series might one day recommence from the exact moment it leaves off.
Walking Dead's Real Ending Is the Triumph Fans Deserved
Kirkman Ensured the Comic Will Be Remembered as a Classic - Something the Original Ending Wouldn't Have Achieved
By depicting a criminal trial where an adult Carl Grimes has killed a zombie which was someone else's 'property,' The Walking Dead #193 manages to check in on essentially every living character, showcasing the romances, conflicts and further lives of everyone the reader could possibly care about. Even characters whose stories aren't strictly over - like Negan, living in isolation after being won over to Rick Grimes' vision of humanity - are given a satisfying sendoff.
That's not to say the ending is schmaltzy - Carl's worries that the new generation of humans don't fear the undead enough to stay safe are clearly justified, and while he's cleared of criminal charges, it's clear his life will go on with further conflicts on the horizon, including two major human settlements finally being joined by a railway. To some readers, Michonne clearing Carl of a crime because of their experiences together suggests that the new, 'better' human society is recreating the corruption of the old.