I did a poll on this not long ago. If anything is to be learned from it, it's that people just get side tracked. Not many admitted to just signing up regardless.
https://forums.frontier.co.uk/showt...any-CMDRs-sign-up-to-CGs-but-don-t-take-part?
To be fair it is 137 participants in that poll.
That isn't even 5% of the participates in the CG screen shot two posts above at the time of posting and 1.5% of the Moari CG participants.
Add to that 10% were "I never sign up, not interested in CGs. "
For a voluntary opt in poll in a separate location to the CG sign in, ie forum vs in game, I would not say anything, at all, could be ascertained from the results presented.