Zuckerberg changed his mind on this in an interview in 2014:

"I don't know if the balance has swung too far, but I definitely think we're at the point where we don't need to keep on only doing real identity things," he says. "If you're always under the pressure of real identity, I think that is somewhat of a burden."

https://www.csoonline.com/article/2226288/microsoft-subnet/a...