I am of Turkish origin and have read "Snow" in its original Turkish print. I feel that the reason why there are so many lukewarm reviews for this book is that the themes & references might not be so accessible to readers who are not quite familiar with the culture and recent history of Turkey.
One underlying theme of the book was that the protagonist Ka is living in exile in Germany (a situation many Turkish intellectuals & political activists found themselves in, following the 1980 coup d'etat in Turkey) in a small state-subsidied apartment, a lonely outsider in a foreign culture. All this alienation and need to belong are, I feel, behind his thought that it would be a good idea to marry a girl he has fancied back when they were both little, and even his rapproachment with the religious groups.
The whole thing is a nod to feelings of isolation reported by the poor, uneducated, "rural" Turks who went as factory workers to Europe decades ago, and whose descendants still import brides from Turkey. The book seems to be saying that those of us who are better educated, who consider ourselves above our "rural" countrymen, are still the same down inside, with the same cultural longings.
Another theme is the play on names. All Turkish names and surnames mean something, and most are words that are still commonly used in everyday language - Rock, Fire, War, Peace, Rain, Water, etc are all given names in Turkey. The two female characters in the book are Ipek ("Silk") and Kadife ("Velvet"), for example.
Going back to the play on words - KARS is the name of the city, 'Snow' is 'KAR' in Turkish, and KA is the name of the main character. What might not be so obvious to the foreign reader is that no Turk would be called "Ka" - it is too short, and above all, it does not mean anything. Author could be trying to show that the protagonist has lost all meaning, cultural relevance as well as the "meaning" of every Turk's name. He is set apart from the culture he longs for, even in his name. The whole wordplay of "Kars > Kar > Ka" not only links the place, the blanket of snow that isolates the city from the world, and the protagonist, but also seems to be pointing towards a diminishing effect, a reduction to absurdity.
One last thing I would like to mention: "Mavi" ("Blue") is not a name in Turkish. It is a code name, with heavy reference to "Yesil" ("Green") - the code name used by a Turkish ex-cop, ex-MIT (Turkish CIA) assassin used by the state in 1990s for illegal executions.