As a man who cares a lot about Tznius issues and his Ruchniyus, Im really sickened by some of the men commenting here. Dont you men realize that shmiras eynayim means watching your eyes? You have no business even looking at your friends wife. If you are truly makpid to only glance for the purpose of not bumping into them you will not have issues with where they congregate and all that. It seems that some of the men here are looking too much and that is what is bothering them. Face it, we live in a Pritzusdik world so even if you never saw a Jewish woman in the streets youd see so much prustkiet just from billboards and the way young non Jewish women walk around.
If you are busy watching your eyes, I dont see how some wives sitting outside with their babies really poses a problem for you unless your Tayvos are out of control and you cant resist looking at women. In that case you are the one who should be indoors and not walking the streets. NOT THE WOMEN!
As aries said, the women have lots of kids and lots of responsibilities and they need to go out to air out and socialize as well as take the kids out to play and they need to be there to supervise. Have some Rachmanus and cut the women some slack, unless you want to take care of the 5 kids under the age of 10 yourself!