What makes this particularly bad for iOS users is the fact that you cannot delete a wifi connection if you're not there. The interface just doesn't show all your previously authenticated networks.
So imagine that you travel, go to a few hotels and use their wifi networks. Once you're back home, the fact that you used these networks is still broadcast everywhere, and there is no way in the interface to turn that off.
This is especially frustrating as a transit user whose bus goes by multiple Starbucks/local cafe chains. Even at 40 km/h, that's enough time for my phone to say 'WIFI NETWORK MUST HAVE', which results in my internet suddenly not working anymore until I figure it out and turn WiFi off entirely, forget the network (if it doesn't disconnect before I can get at it), or just finish an article while it times out.
So imagine that you travel, go to a few hotels and use their wifi networks. Once you're back home, the fact that you used these networks is still broadcast everywhere, and there is no way in the interface to turn that off.