An ecosystem in phone-context means a self sustained market for commerce where all levels and all needed units exist to sustain it. That is why it is called ecosystem - a self sustained system. The goal is not the system itself, but the end user. The end user must feel that the ecosystem increases the value of the phone, and therefore he is willing to pay, and thus contributes sustaining the system and making it grow. A big mall with stores, cafees, restaurants and so on. An ecosystem needs consumers.
A FOSS ecosystem tends to become only about building the system, building the core structure in an atmosphere were most of the consumers also are the producers. It is self sustained and all, but never gets polished enough to attract paying customers. For the average user it is a half finished and empty mall where no one understands the meaning of the word service. Such a system is OK for developers, but totally uninteresting for consumers.