What I am hoping - and what I have contacted Ancestry regarding - is that we will be able to connect and share information with our matches in the manner available to the customers of 23andMe. Yes, one does have to take the time to contact matches and request sharing there. After the connection is made, though, family trees may be viewed by matches but not by the general public (if this option is chosen).
There are a number of reasons for keeping a family tree private on Ancestry ... many of which have been expressed previously. Most importantly, it seems unwise for anyone to make available the degree of information that most open trees allow access to.
For me, the luxury of having a public family tree lies in the unbroken connections which most people's trees exemplify. Mine is fractured and open-ended due to adoptions. While progress has been made on these lines, it might not be readily apparent in a public tree.
I also have needed to attach the genealogies of genetic cousins to my own in attempting to discern these adoptive roots, and their family trees are not mine to share.
Prior to testing at Ancestry a couple of months ago, I was uncertain of how this service would work. I did assume that at least the common surnames of matches would be mutually viewable; that there would be something available for everyone to guage where a connection might lie. I'm sorry about the frustration that private trees are causing, but Ancestry itself needs to be addressed so that the system can be improved.