Simple math.
But here is the closest I can find to a vote.
“With more Scouting troops than any other religious denomination in the country, the backing of the Salt Lake City-based church was significant for the Scouts.
Following church leadership, Utah’s two main Boy Scout councils — made up nearly entirely by LDS Church-sponsored troops and among the largest in the country — also backed the rule change.”
Thank you. I feel my suspicions have been confirmed.