Many higher end smartphones already support WiFi. Bluetooth is still great for connecting user interface devices like headsets/mics etc. But for the other things you mention, WiFi is better.
One of the posts above quotes from the Android development team saying they understand there is demand for Bluetooth. Perhaps it is simply they feel there are more pressing priorities right now.
Could also be that their product manager feels that support for Bluetooth peripherals is all that is needed and the rest will be handled by WiFi.