Having the existing members vote on new members for the current year risks the criticism that the council could become a 'privileged club' whose members continually back each others participation.
For example, I have an issue with the work of the Foundation. I decide that one of the most effective ways to seek change ought to be to apply for membership and 'be the change'. However, my application is rebuffed, and the committee remains the same. I then take to social media to complain that the membership voting process is conducted 'behind closed doors' and works to people who are critical of the current advisory council from being elected.
Whilst the board might be good people, and I might have been rejected for valid reasons, the lack of external input to the makeup of the board means I can now characterize my rejection as a refusal of the Foundation to respond to criticism on social media.
So I think we need a process that allows external input into the decision as to who the members are.