As someone whose coming-of-age was decently influenced by Boy Scouts, I have to say that I welcome this change, so long as the Boy Scout program and the new Girl Scout program stay sufficiently separated.
Scouts was in-part a great experience for me because of the male-bonding and what it taught me about manhood, maturity, fraternity, and masculinity. It was great in other ways too, teaching me about leadership, unity, communication, responsibility, discipline, appreciation for nature, values, duties, and obligations. I don't see a reason why there shouldn't be a program for girls that aims to do the exact same thing with womanhood, sisterhood, and femininity.
I was never in Cub Scouts, so I can't speak to that as much, but it does seem to me that Cub Scouts is much more of a fun activity for your kids to participate in while the parents take turns chaperoning than an actual character-building program. The already-existing program, while they don't *just* sell cookies, their program is very watered down and fluffy compared to Boy Scouts. Again, it seems more like just some extra-curricular activity than anything that could really build strong character. Also, it's a different organization, so BSA can't just change the program because it's not their program. As for Venture Scouts, I never did that either, but not only does it seem to serve a different purpose, but it's co-ed meaning boys and girls together in the same group.
And just a little disclaimer: I had a much better experience in Boy Scouts than most. My troop was extremely well led and well organized by some really smart people and great leaders. Unfortunately, after about four years there was a changing of the guard, and from there on out the experience was much more lackluster experience more akin to what most people have. While I recognize that many people who try scouting will not have the experience that scouting should be, that doesn't change how I feel about the opportunities that girls could have to have a similar experience.