Indeed. Evidence shows that users understood the changes - 50% of users select something besides the defaults, and Facebook has been open with those numbers. This is after millions of users in countries like Turkey already had effectively public profiles.

  An average user, certainly, has no idea what is going on by these changes.

He ignored the public stats in order to make a point.

Further, this change is important, and there was a lot of work and testing to make sure people understood the results. Jason assumes his intuition about what users understand is more accurate than this research.

In other words, he doesn't know what he's talking about.