Because they make sure the game works.

Because yearly nonsense dominates US more then Japan. In US you got CoD, sports games, AC, pokemon all yearly as of late.

In Japan MH (not yearly), Pokemon, Final Fantasy (not yearly).

Yokai watch is a recent new ip that is released every half year though.

When you have two or three teams designated as COD or AssCreed factories and reuse assets and engines ad nauseam, it's easy to pump out annualized games.

Cause waifu's need to look as hot as possible

Quality over quantity.

Call of Duty and Madden are basically the same game every year, especially Madden. EA and Activision are the 2 greediest 3rd parties. Meanwhile there are loads of series that actually do take more than a year to make an iteration, like Far Cry, Halo, and Gears of War. EA and Activision mostly aren't interested in making an art piece that will sell. It feels like they want anything that can sell. Masahiro Sakurai created every Super Smash Bros. game as if it were the last game in the series. Some companies know that their game'll be back by next year.

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.

Because they are not annual games that are pumped out each year :/

You know Ubisoft Montreal? They're the main developers behind Assassin's Creed, Watch Dogs, and Far Cry. It has a total of over 2700 employees.

You know Nintendo's EAD division? Its Kyoto teams are the developers behind Mario Kart, Animal Crossing, Nintendogs, Splatoon, Zelda on consoles and handhelds, New Super Mario on consoles and handhelds, Pikmin, and Star Fox. There are about 720 employees there, not even 30% as many as Ubisoft Montreal.

It's easier to make more big games more quickly when you ad another digit to the team's size.

Don't you guys think Japanese developers should increase their teams then? Also is this the only reason or are there culture reasons behind it? I remember Sakurai saying that instead of finishing a game they would keep modifying it?