This thread has largely devolved into a "Will Not/Will Too" conversation. The opinions are so clearly opposite as to what will or will not improve sustainability, and no one seems to be shifting position, or even
understanding the other side's arguments, as though we're having two different arguments. As a first hack at this apparent Gordian Knot, I'll ask (and answer) the question:
What does FRC sustainability mean to you?
My definition derives from a more general definition I found on line. Applied to an FRC team, to me it means:
The ability of an existing active FRC team to continue being an active FRC team indefinitely.
As lack of sustainability is the primary source of team attrition, attrition rates (or more precisely retention rates) are a good first order measure of team sustainability. Teams can improve their sustainability through diversification of their various resources (mentors, students, money, facilities, supplies), and even more so through implementing a plan or culture through which new mentors, students, and sponsors are regularly identified/recruited at least as fast as the existing ones cease.
Does FRC sustainability mean this, or something different, to you?