It should be the opposite. Always. A woman who does this doesn't contribute to the "friendship". Her benefit for you is always her network and that she makes it accessible to you.I have a lot of female friends and it doesn't take away the need for those things at all. It helps in some ways but it doesn't yield many more opportunities than without. Getting invited to party with them is the biggest one, but she often has gossiped(sabotage) about you before hand to her friends and even a well meaning friend can't control the negative turn gossip usually takes. They also tend to hook you up only with their least attractive friends, which shows they view you as low SMV (hence just being friends).
Another benefit would be if she is a validating person, or someone you can just have fun with. It should really go hand in hand.
I think these are fake female friends. They don't value you enough, so they toss you to any woman who is really desperately needing a BF right now. Because they value that friend more.