I'm sure it has nothing to do with engine work, or what is or isn't possible on the 360.
Sega made the game ps3 exclusively in the first place because 1. they were already working on a ps3 engine due to another game - Initial D: Extreme Stage, which was released only in Japan, and 2. it's in a genre that sells predominantly in Japan, so why hold up a ps3 version just to port the game to a console that has sold horribly in Japan.
While they may have pondered a later port, they probably decided against this, because late ports generally don't sell near as well as the original release, let alone a late port to a console that is not popular in the main region for a title like this.
The game has garnered almost half its sales from Japan, and it still sells decently in Japan, while in NA it's practically impossible to find since GameStop's GameDays sale a month ago. Sales are now dry outside of Japan. A 360 port would probably sell under 100k lifetime. Would that be worth it?







