Maybe they should rename it The Manhattanite, or maybe The Manhattanite, Preferably Below 14th Street.
If you slice off the more residential areas, of course you'll wind up with a big population with a smaller level of cultural activity, because cultural activity is often concentrated away from residential areas: people commute from Queens to Manhattan, and then they stay there to eat/drink. That's an oversimplification that doesn't apply to everyone... but that's the broad pattern.
For reference, according to http://a816-restaurantinspection.nyc.gov/RestaurantInspectio... Manhattan has about twice as many eateries as Queens. But that doesn't tell the whole picture, because a greater proportion of those Queens eateries are likely to be neighbourhood places, diners, delis: places that the New Yorker is obviously not going to review.
So yeah, there's probably some bias... but destination restaurants are concentrated in Lower Manhattan. That's the way it is. You should expect New Yorker reviews to reflect that.
In Manhattan every single address ends with "New York NY" and in Brooklyn every address ends in "Brooklyn NY", but in Queens the addresses correspond to the individual "cities" or rather neighborhoods that comprise the borough. So instead of "Queens NY" addresses end with "Long Island City NY" or "Flushing NY" or "Jamaica NY" despite being in the city of NYC.
So maybe this side project, which presumably is based on scraping the data from the New Yorker site, doesn't have all the various areas of Queens coded into it.
Or maybe it does, I'm just speculating wildly without actually looking into the matter.