Why not StarCraft 2
BWAPI was created by reverse engineering BroodWar and relies on reading and writing to the program memory space of BroodWar in order to read data and issue commands to the game. Since any program that does this can essentially be seen as a map hack or cheat engine, Blizzard has told us that they don't want us to do anything similar for StarCraft 2. In fact, most of the StarCraft 2 EULA specifically deals with not modifying the program in any way. We are happy that Blizzard have allowed us to continue using BWAPI, and they have also helped out by providing prizes to the AIIDE tournament, however until their policy changes we will not be able to do the same for StarCraft 2.
Other minor reasons:
- In the interest of academic development, Broodwar is cheaper, and its hardware requirements are lower than StarCraft 2, making it more accessible to university students. BWAPI is actively being used as university courseware (professors are actually using BWAPI in classrooms).
- The Starcraft 2 engine is not ideal for AI development. We can increase the logical frame rate of Broodwar easily, so that games can be played more quickly, allowing some AIs to learn more quickly.
- AI/API developers will need to handle far more information than with BWAPI.
If you still want to use StarCraft 2, check out this porject.