The golden badge for Great Question was awarded only once. Why there's so little highly upvoted example questions? What can we as community do to encourage voting for really good questions? Maybe the requirements for Proposal phase should include at least "a few" questions with "a lot" of votes, without revealing, what those numbers are?
The desired behavior driving that badge was derived from the main Q&A code. High quality posts are rewarded over just asking (and gaining votes from) a lot of mediocre questions.
Unfortunately proposal followers are typically more interested in thinning out their votes across more questions to push the proposal through rather than voting for their favorite (great) questions. But that doesn't change the end goal of having that badge in the first place.
There are no plans to change the 'Great Question' badge.