You forgot 1.1 – FooLabs takes hundreds of millions of dollars in VC funding and these VCs want to see a 10x return on their investment, which is incompatible with keeping the software free and open source.
Sure. Presumably also the developers at FooLabs would like to continue having a job developing Foo, and the broader software community would like to continue benefiting from additional features and improvements to Foo, which probably wouldn't happen if developing Foo was economically unviable.
