Many people think that the best thing for projects like this is to have as many entities involved as possible. Anything that is controlled by single entity is bound to forget the needs of others.

For example: neither Mozilla nor Amazon might have Embedded Systems as a core interest, so they will forget about it and might accidently make decisions that ate bad for this use cases. If you also have ARM, Microcontroller vendors and so on on board, they will make sure that this topic isn't overlooked.