Boy Scouts' membership began falling in the 70s as society's anti-Vietnam sentiments leeched over to Scouting. Membership rebounded during the 80s/Reagan, then began a free fall in the late 90s. The Girl Scouts' trends generally followed that of BSA
To be sure, this membership fall accelerated with the SCOTUS 5-4 ruling in favor of BSA's banning of gay Scouts in the 2000 landmark case BSA v. Dale. In part, as a result of that ruling, many Troops lost their sponsorship at the local level. But, and this is key, it is the Troop leadership that runs the show, not national or even the district.
Around this time, National started sweeping these abuse cases under the rug. This is a shameful and reprehensible act, and National's bankruptcy filing is richly deserved.
But this BSA erosion also coincides with a general decline in children participating in "organized" activities like sports. Thus, this a subset in the story of the general decline in children's participation in organized activities.
A few years ago, BSA National started floating balloons that "our research shows families like to do things together, and to tap into that well of parents with sons and daughters we will open up Scouting to girls, with separate but equal logistical setups." There wouldn't be co-habitating, showering together etc like mindless idiots spouted. The only overlap would be that campgrounds could have boy and girl Troops there simultaneously, but that's about it.
Many of us in Scouting leadership rolls called this plan what it was.. a Hail Mary pass to forestall continued financial hemmoraging caused by falling enrollment and rising legal costs. Notwithstanding the partial merits of a father spending a weekend with his son AND daughter, and that not all girls would WANT to join Scouts, fundamentally, a program of building the male leaders of tomorrow with a century of proof will no not ipso facto work on girls. Thus, while National pushed this farce, many Troops rejected it.
Meanwhile, the Girl Scouts had their own problems, and now see BSA encroaching on their turf. Ergo the cat fight.
It is, sadly, fashionable to bash Boy Scouts. To be fair, I've heard from many people who tried real hard at the Troop level to maintain a Boy-led Troop that relies upon the classical program that works. Alas, social engineering has taken hold in some Troops and these men have thrown in the towel. And, again, the tolerance of pederasty in the ranks is grounds for a good keelhauling. I get it.
That said, for every real-life "I tried but it didn't work" story I've received, there are countless uneducated people who post and spout off (usually on FR, I'm sorry to say) that "the Scouts are now gay" Blah blah blah. I can usually tell these Dems-in-training because they rarely ever have an actual story to retell or give witness to their efforts to strengthen youngsters through Scouting. That is likely because - wait for it - they haven't any clue what is The Scout Law or The Scout Oath and haven't been to a meeting in 10+ years (if ever). It's easier to have some cheese with the whine.
I'll be blunt: most people who actually TRY Boy Scouts with their son and participate AS A LEADER, will find great success at the Troop level. The program is sound, and if you don't like what you see you can move to a more like-minded Troop. There ARE Red Troops, and it helps if Dad is there influencing the agenda at the Committee level.
Yes Virginia, there IS still a place in Boy Scouts for boys to learn masculine leadership skills, but (here is the kicker) it requires EFFORT - something our keyboard warriors severely want.