We have reached a critical inflection point for open source.
With everyone from Qualcomm to UBS to Microsoft embracing open source in one shape or another, the question is no longer "why" to use open source, but rather "how."
Because of this changing mindset around open-source adoption, we no longer need evangelists encouraging open-source adoption. Adoption is a given. It's the default.
No, what we need now are those that can illustrate how to derive the most benefit from the inevitable adoption of open source.