Why do Japanese developers take so long to make a single game?

[LMU Uncle Alfred]

I don't think Japanese companies have as many people working on each game as US developers do.

Edit: Leaving aside the obvious yearly releases, this was in response to a previous user on how Japanese studios work.

I think there's a difference in philosophy as well.  There are belief differences on how things are and should be in the west and as opposed to the east.