What you're missing is that people who don't have anything to hide don't want to be forced to adopt hiding practices, even though that might benefit other people. The choice to give away privacy in return for convenience is as much a feature of liberty as the choice to do the opposite, notwithstanding the disutility for a minority that can arise as a result of network effects.

I'm not missing anything. I understand that point entirely:

"Doing X benefits me. Sod everyone else"

I am fully aware of this attitude that many people seem to have.