You refer to the characters "surviving" or "enduring", so let's see a situation where they might actually be able to survive. If they never had a chance, you can't say the show is about survival.
Uh, I don't think the word survival means whatever it is you think it does. The show so far has been exactly that; them surviving in a zombie apocalypse.
So, will the last episode see everyone dying, Rick turning his gun on himself, and the screen fading to black while the walkers close in? If so, why watch?
Again: The same damn reason you watch any other show set in a persistent world, including our own. Very few stories have
this non-existent ending you seem to be desperate for. Very, very few. Even the ones originally mentioned never ended. Voyager returned home, yay! And I guess after they did, they all retired from Starfleet and had no more adventures, and the entire Trek universe came to an abrupt end? No. Battlestar Galactica had the survivors (there's that word again) reach our Earth... so after the fade to black, they all died and nothing else happened? No.
It's the same thing here. The only thing the Walking Dead lacks is a major
goal. But, yet again, that's the norm in vaaaaaast majority of shows. And even when there is a major goal, that's not always the end point for
the show. Farscape
is a prime example; the main goal was for Crichton to get back to Earth. But that's not where the show ended.
The Walking Dead
is simply a drama/soap opera/character piece. There is no ending, because all the stories are about the characters living in the here and now and, once again
, how they struggle to survive in a world where there is no hope for survival. That's it. That's the story. That's The Walking Dead
If that's not enough for you to watch it, why are
you watching it? And why do you watch most everything else you watch?