Universal login question about Buddypress

I have buddypress installed with a WP multisite. I'm surprised that a user (even a super admin) doesn't have the ability to simply login once and be able to access everything within the buddypress network. As it turns out, if I login in to the main blog using BP, I still am required to login again on another blog site if I (or a user) wants to comment on a blog post.

To me this seems a bit of a an over kill. Shouldn't it be enough for a user to login once and have access to the entire network?

If this is possible and I am missing something please let me know.

Thanks.