The entire sixth season was about cheating a fixed timepoint because only the history was fixed, the presumed events underlying the history could be incorrect and were subject to change or reinterpretation. History said the Doctor died at Lake Silencio, so the Doctor faked his death and preserved history. Seeing that same character give up immediately because he read a mass market paperback was baffling. Granted, they said the timestream was screwed up in that era of New York, but ... I don't know, show up five years early and wait, or go to New Jersey and take a train, then buy a plot in the cemetery and put a headstone over the empty grave? And River, who had independent time travel technology, didn't try anything either. If she had zapped away and come right back with horrible injuries because of timestream damage, I'd understand Amy telling them not to come back for her ... but River just gave up immediately and encouraged her mother to exile herself in the past. This is the woman who broke time because she didn't like fixed points. For her parents, I think she'd at least think about it for a few minutes. You know, "last time was a disaster, but this time I'll do it differently," that sort of thing.
I liked Moffat's first two seasons because he was trying to tell long stories that utilized Doctor Who's unique qualities, and he was mostly successful. This one was lazy and, as much as it was superficially related to his other work, was really disconnected from it.