the industry is like this in general. you can throw in 'western-developed' for good measure.
Which industry are we discussing here? The review industry? Because then I agree, although the preference for Western development is relatively recent (i.e. last 5 years).
I'm not really sure if I ever see that going away though, especially how GAF votes with a top 10. Not all the time, but in general the time commitment for most multiplayer games (especially if you are picking one as your GOTY) is quite a bit larger then the commitment to finish a story based game. And as such, even a hardcore multiplayer game is relatively likely to only have one or two multiplayer focused games in their top 10 list, and in many cases will also have a few single player games as well. I just see the average gamer being able to finish more single player experiences in an average year, and as such they are going to bulk out the top 10 lists. Multiplayer games are just too all or nothing with a players time to get enough votes to really break up the top lists.
This is rational, but of course you can also do what I did; just not post 10 games.
This then begs the question why someone would want to play single player games in the first place, presuming you also enjoy multiplayer. If you can get more/longer fun out of the same cost, why wouldn't you do that? It seems unnecessarily expensive.
Of course, if you don't like multiplayer at all, then all bets are off. I pity such people, from a purely objective viewpoint; your gaming hobby is much, much more expensive than mine.