I feel confident that the BSA will do the right thing as well, but as with many anachronistic customs based on illogical fears and prejudices, it has taken time.
The reason that I believe the BSA SHOULD end their ban on gays is precisely BECAUSE of what it will do for impressionable young boys. You see, I don't think gay is a disease or a choice, so there ARE and ALWAYS will be children who are gay (not that it is relevant when they are children, but it is still what they are) and they ARE impressionable. The impression I would prefer to give them is that being what they are is perfectly acceptable. Making people hide what they are is one great way to crush a person. Allowing people to be opnely gay does not mean allowing people to have gay sex in public, it just means allowing them to admit what they believe they are.
I don't believe either of my children are gay, but I want them to know that if they are, it's fine by me, I will love them for who they are, not their sexual orientation. My children are aware of my stance on this, and they are aware that I believe that organizations that discriminate in this way are simply fearful backwards people who will get old and die and take their prejudices with them.
Go take a look at the hundreds of thousands of conservatives who have reversed their position on this issue for one simple reason, they learned their own child was gay, and in that moment, they come to realize that gay people are not something to fear, but people who want to disciminate against their children over this simple fact of their child's nature are the people to be feared.