If you read the announcement they're letting local Cub Scout packs decide how they want to handle it but they are having separate dens for boys and girls. I'm a huge believer in Cub scouts as a developmental tool and have no problem if there is a local demand and packs want to set up dens for girls in the community.
I would have a much larger issue if they forced mixed gender packs. That would be a big problem.
You are very naive.
What about the Girl Scouts is lacking that makes some young ladies ( or their mothers ) feel it is necessary they be allowed to join the Boy Scouts ? Some say the color line is blurred . . . . and the gender line is apparently now a little more blurry as well.