You admit that other girl scout groups were doing the same as the boy scouts were doing, but the leaders in your group didn’t want to. The issue isn’t boy scouts getting to do something that girl scouts can’t. The leaders in your area just didn’t want to do it.
I was a boy scout for awhile and the single sex environment was great. Now with the inclusion of girls, that element goes away for boys (but not for girls in girl scouts I presume).