Whether this is intentional is not clear to me, probably not.

I think it was intentional -- other characters frequently remark on how dumb she is. My impression is that Swan's character was some kind of artistic/political statement by Robinson -- that the adventures of a screwed-up, clueless person are just as valid and meaningful as those of more traditional heroes, or something. I wasn't too impressed by this, but the book's worldbuilding was amazing and that made up for everything else.