A novel is not a historical document, but it does become one, regardless of its author’s preference. Our entertainments reflect their times: how we choose to remember historical events, and how we prefer to remember them. Especially when the worst of times, World War II, becomes material for the lightest of entertainments.
Emphasis mine, in big part because of how it echoes something I've been reiterating in various venues: all entertainment is art whether or not we want it to be, so we owe it to ourselves to make better art.
A lot of folks in the business of making art-of-a-kind don't see themselves as artists, but craftsmen or entertainers. The former is not nearly as odious a view as the latter, although that isn't to say I think entertainers are contemptible people; I just think it's a terrible idea to shortchange yourself pre-emptively, and by that token to shortchange others. Everything you have to say, even in jest, becomes a part of someone else's worldview, even if only a tiny part of it, so you need to watch yourself.
I haven't read the book in question, so a lot of what I say in this realm is limited. But from what I've seen in other books that made the same kinds of mistakes, It's hard not to take on a subject as broadly grim as WWII or the Holocaust and not run the risk of becoming pompous (the review's own adjective) and self-important. A project like that risks becoming less about its subject matter, and more about having the author wanting to invest himself with seriousness and self-importance: Look, I wrote a book about the Darkest Chapter In Our History, aren't I noble?
This is also not the only book of critical note in recent years to take what amounts to a stance of malign equivalence on WWII — that the Allies were just as bad as the Nazis "in their own way", or something along those lines, an attitude that serves no discernible intellectual purpose except to give all the wrong kinds of ammunition to all the wrong kinds of people. But more on that another time.
Anyway, the big reason I brought this up was to comment on how the distinction between high art and low isn't always a function of the creator's intentions. Just because we want art with every fiber of our being doesn't mean we get it. If, as someone else put it, your thirst is for the Pulitzer but you only put out potboilers, you need to realize this and figure out what to do about it. Some would say the best answer is to write honest potboilers, but even an "honest" potboiler has to be a kind of art, too.
No matter where you go, there the art is. You might as well do as good a job of it as you can.