Not affiliated with BSA, but the Civil Air Patrol Cadets was also a very similar environment that was open to everyone. Also wasn’t a problem there. The real doom and gloom prophecies people are putting out are just total nonsense.
The only real objection to opening up the Boy Scouts to girls I can see is that, it can sometimes be helpful to have reserved spaces for one gender. That’s true for both boys and girls. There’s a lot of things that are just more comfortable for both to do or talk or learn about without the other one around. That’s true even for adults I think, but its especially true for teenagers dealing with becoming adults.
I’d still come down in favor of allowing girls into the Boy Scouts, just because the Girl Scouts are such a totally different experience, and girls who aren’t interested in that and want the Boy Scout experience miss out. I’d also say Girl Scouts should open themselves up to boys. Boys who aren’t really interested in camping and hiking and whatnot would probably have more fun in the Girl Scout environment. Both could probably change their names to something more appropriate as well. This is probably wishful thinking though, Girl Scouts has much more invested in their brand name.
But I do wish we could also come up with more spaces to deal with what I brought up. Maybe within this new co-ed environment, they could still have one or two events a year where boys and girls go and do their own separate things.