It is quite normal to have some inactivity after a season of JDC ends. Ninety-seven (97) players earned points during the last JDC. Plus last year, 2012 contained three seasons of ladder, which seems a bit much.
Personally, I usually break from playing JJ during JDC itself, not to drown the spirit of competition but everyone could use a break.
Interesting question about JJ1. I have recently played the port of JJ1 to Windows Phone since I got a Nokia Lmumia a few weeks ago.
The port is fun and works well with touch screen controls. It only contains the first episode though. Anyway JJ1 for Windows Phone is being updated more to version 2.5, so I wonder how they will improve it. They say the game has over 100,000 downloads.