> The JVM is fine for running low-latency automated trading systems.

1. There is a lot of expert tuning to get that sort of performance with respect to latency. That tuning would need to be reproduced for every target system.

2. Those trading systems can have ridiculous amounts of RAM to give the JVM GC lots of room to work with.

3. Reading packets from a wire and writing other packets to a wire is a different problem than reading controller inputs and modelling complex 3D worlds.

...that's not to say you can't have AAA Java games. To some degree that already happens with Android games, at least if you're willing to stretch the definition of AAA. (If you define AAA as "uses C++", the nomenclature becomes fairly moot).