Neither the paleoclimate stuff nor the Great Terror paper tend to deal with causation at the level of seriousness we'd usually hold a natural science paper to. I can't in one paper claim to have determined the cause of e.g. intermediate depth seismicity--reviewers would rightly tear that apart.
I agree on the point about how these papers deal with causation. It's also true that natural scientists often disagree about what exactly is needed to establish causation and how to accurately describe results in that respect.
Within specific fields or subfields, there's often a roughly defined range of what's an appropriate claim. That isn't true for these papers where the claims are at least partly in an area outside the authors' expertise and experience.
Good point! That also makes it seem there's an issue who the editors are soliciting reviews from (or at least are able to get to agree to review).
Yes, and worth noting that Nature and Science need multiple reviewers who will respond quickly.