Lets see...

J.B -hopes for that stockpile to end all stockpiles.

Jak -looking for retribution for his lost wife and child

Mildred -Looking for things from the past as a reminder of just what she has lost

Ryan -Thniks he is in charge but just follows Krysty's orders...

Jim

Ryan and JB have said several times that they couldn't just "settle down" - they've spent too long on the move. It's like old people when they retire - they've worked most (if not all) their lives, and suddenly they have nothing to do, so they either find something else to do, or they waste away. Ryan and JB are like that - if they're not out there roaming the countryside, finding bad guys to kill, they be lost because it's all they know.

If Jak ever found another Christina, I'm sure he'd settle down again. In the meantime, he's happy to just go where the road (or the gate network) takes him.

Mildred... well, who knows with her? I think she'd settle down, under the right circumstances - she was never really cut out to be in DL, and she's tagging along with the group because they're her anchor in a world gone crazy.

Doc, of course, wants to find a way home.

I feel that as they are written the only one who really wants to settle down is Krysty .
Doc wont settle down because that would mean giving up on his dream of going home .
Mildred might settle down ,but like Doc ,I feel she really would like to find a way back the life she had before.
Jax is never going to settle down because the last time he tried that it was a disaster.
For Ryan and J B I Feel that they will never settle down they have been on the road for too many years . They would miss the excitement of travelling to new places too much to settle down.

I think that the "Gang" should find somewhere to settle down but go out on "missions" and so forth, to find provisions and equipment for there new "home".

I think the first book shows the main reason they wander, page 25: "It is even whispered that there is an escape route: that somewhere, beyond the Deathlands, there lies a land of 'lost happiness.' Absurd, of course. Irrational. A foolishly nostalgic dream conjured up to compensate for living a life of horror in a land of death. Or is it . . . ?"

Like seen in Crimson Waters, even if you DO get such a decent place, you will have to fight to keep it.

As far as FICTION goes, the constant movement is smart--keeps a constant freshness in plot, new settings, new characters, new dangers--conflicts and changes make for fun stories. And allows the characters to really shine, personally and together as a team, as they have to continually face new stuff. The redoubts and their cool transportation abilities is another smart plot device for the series--like the constant movement of the companions--it avoids the long boring travels, keeps them neatly in supplies, provides 'down time' or added danger depending on the redoubt itself, and lets the plots stay swift.

Basically, if you want to keep the cool action/adventure of the series, they CAN'T stop.

One of the things that bothers me about the series, indeed. I guarantee that no woman is going to want to roam around in perpetual homelessness for too many years. Eventually the women folk are going to want stability and security, its hardwired.
Believe me, a woman with any self respect won't stay long with a man who doesn't have anything to offer in ways of security. No scrubs, as the ladies say.