I'm not desperate for a fairytale ending. But having no goal is a problem. If they have no goal, then whatever ending they achieve will only elicit, "meh, so what?"
But they have a goal, it's "Don't get eaten by the dead or murdered by the living", I'm not sure what you're expecting, this is not a quest where some people search for a magic stone, turn every zombie back into a living human and magically restore society to what it was before with a redeemed and living Shane making sweet love to Rick (because Lori was clearly an incarnation of the evil that wanted to kill them all).
What kind of shows do you watch because I can't think of many that have a set goal that the characters have to reach, usually the goals are things like get money, find love, have fun or help victim of the week.
But I do see what Silvercrest means. I am quite confident that the writers will give us some kind of dramatic closure, which is always the most important for me. Something that wraps up the themes and provides structure to the character arcs is very common in television series. TNG did this quite well, and Lost (despite its plotholes) did this effectively as well.
In addition to that, I bet that we will get more answers as to how the outbreak happened.
I think what we're asking for is something like, say the group either finds, or is found by, a city where they have essentially rebuilt civilization, however, having the "new normal" of zombies factored into the daily routine. (That city might also be established by the group).
The final season might be the group really trying to find the :secret" of the group, but realize at the end that the safety of this city is real, and not fake like Woodbury.
In the last episode, I might expect Carl or Judith reminicing about the "old days", and we see the new normal as the closing (and maybe someone slicing a zombie head as the last scene).