In a letter to Sarah Orne Jewett, in 1901, Henry James inveighed against historical fiction:
"You may multiply the little facts that can be got from pictures & documents, relics & prints, as much as you like -- the real thing is almost impossible to do, & in its essence the whole effect is as nought. . . You have to think with your modern apparatus a man, a woman, -- or rather fifty -- whose own thinking was intensely-otherwise conditioned, you have to simplify back by an amazing tour de force -- & even then it’s all humbug."
The flaw in this argument is that there is no "real thing," if by this James means something like perfect fidelity to the zeitgeist. That "real thing" is always out of reach, even in writing about one's own time.
When writing a contemporary novel that alludes to current social and political events, one draws to some extent on journalistic sources -- perhaps the same sources that a novelist a hundred years from now might use to recreate our own era. That future novelist will make mistakes we wouldn't have made, but will also have a perspective on our own time that we can't have. Writing contemporary fiction, one sees more of the trees -- writing about the past or an alternate past or the future, one sees more of the wood.
Understanding this, readers don't expect Andrew Sean Greer's 1953 to have the same flavor as Richard Wright's 1953.
Nobody, after reading Patrick O' Brian's Master and Commander, thinks O'Brian would have done better to write about the late 1960s, the time when he produced that work. No occupation could more thoroughly test a man's character than captaining a ship during the Napoleonic wars, and this provides the prefect setting for O'Brian to explore whether it's possible to be a good man, while fighting against nature and external enemies, although one's own society is corrupt. The astonishing contrast in values and attitudes between the late twentieth-century England O'Brian knows and the early nineteenth-century England he envisions only adds to the book's power.
Even those who set out to evoke their childhood in a memoir soon run out of facts, and find themselves tying their material together with webs of conjecture, just as if they were trying to bring to life an earlier period in history. Literature can't help being about what was, and about what might have been, and about what is to come.