Note that she didn't address Facebook, at all. She confined her comments to Google+.

So, while the FB comparisons may be appropriate to conversation here, they do not -- in my view -- imply a weakness in her argument. She left FB outside the scope of what she was saying and whom she was addressing.

P.S. Upon rereading, I do note this bit:

particularly when there are other social networking alternatives with simpler privacy settings.

which perhaps weakens my original argument in this comment somewhat.