I've had plenty of disagreement with Google and Yonatan over many aspects of G+, and have given both the company and him much grief on multiple counts, including Real Names (Google's varient of Facebook's policy), though I'll also note that Yonatan's generally heard me out quite patiently. But his comments strike me as wise and hard-won, painful knowledge:
https://plus.google.com/+YonatanZunger/posts/WegYVNkZQqq
In practice, the forced revelation of information makes individual privilege and power more important. When everyone has to play with their cards on the table, so to speak, then people who feel like they can be themselves without consequence do so freely -- these generally being people with support groups of like-minded people, and who are neither economically nor physically vulnerable. People who are more vulnerable to consequences use concealment as a method of protection: it makes it possible to speak freely about controversial subjects, or even about any subjects, without fear of harassment.
That's quite an evolution of opinion. I respect Yonatan deeply for both conceiving of, and publicly stating it.