Hi! I'm a frequent lurker here, but as I have experience with GSUSA as well as Boy Scouts I'd like to comment on this comparison.
I agree that you cannot equate the two organizations. The one thing that is true, is that the groups are organized very differently from each other, and have a very different culture. Girl Scout troops are not set up as Cub Packs or Boy Scout troops. That can however be a good thing. If there is no troop for your daughter, you can just start one -- no need to find a chartering organization or to set up an entire Pack for kids grades 1-5 and find den leaders for each den. After years of experience with Girl Scouts, when I first got involved with starting a pack in our town (none had existed for years) I was overwhelmed with how much infrastructure a pack needed; it seemed very top-heavy and took almost 5 years to get everything up and running, by which time my son was in 5th grade. If I had just been able to spend the equivalent amount of time on his den alone, he woudl have had a much better Scouting experience. As it is, because of problems getting the pack up and running, we lost many boys in his den and only ended up with 4.
Compare this with our experience with my daughter's troop -- yes, it was only one grade level and not all 5, but we have been able to successfully run a great troop for her and 11 of her classmates and neighbors. I hardly think this system is "selfish" in that we are very open to girls at this level (although we do put a limit on numbers -- 12 seems to be a good size for a troop. If more girls want to join their parents are more than welcome to start a new troop, just as in Cub Scouts you start a new den!)
In our Girl Scout Service Unit, girls who go camping do not camp with parents ala pack campouts. We leaders take the girls camping overnight, choosing to start in 2nd grade. We don't need troop tents or supplies because there are tents at the Girl Scout camps. If we want a propane stove, we just borrow one or bring our own. As girls get older and wish to camp in tents and use more specialized camping gear, we can rent anything we need for a couple of dollars each from our council for the weekend. The Girl Scout program doesn't have camping built in to advancement in the same way the Boy Scouts do, and as a result girls don't often go camping nearly as much as the boys do, but it's not because of lack of gear.
The reason GSUSA is experiencing a decline in membership right now is that they have completely changed their program. They have brought in something called the "Leadership Experience" and "Journeys" instead of badges and advancement, and the girls and leaders are rebelling. Troops refused to do the Journeys and so National made doing one mandatory for earning the "highest awards" in scouting.... but what you actually do to earn the Journeys is almost completely up to you. You just have to say you have done one; the requirements are extremely vague. Girls complain that the Journeys are too much like school; they are also dumbed down.