We've been referring to different things. Since you referred to "indefinite space travel" I thought you were talking about not going to another solar system at

We've been referring to different things. Since you referred to "indefinite space travel" I thought you were talking about not going to another solar system at all, i.e. that "land" meant orbiting another sun. But that was obviously a misreading on my part. Anyway, I completely agree with you that once your ark ship arrives in a new solar system landing on a planet like Gliese 581g would be counterproductive. Instead of having to deal with a gravity well it would be better to make a home in something like the asteroid belt. You only need energy & resources for manufacturing capacity, a gravity well can only complicate that process. People might still want to live on planets as a novelty, or for their resources. But I think any society sufficiently advanced to develop a generational ship that can traverse interstellar space would resemble The Culture (i.e. a swarm of migrating ships & habitats) more than they would resemble The Federation (i.e. people mostly living on planets with ships mainly for transport).