i think it was just poorly implemented. i didn't use the circles feature because all my friends would be in one circle and my family were all offline, but i still had to deal with it for no personal benefit

opt in probably would have been better, like just default everyone to one circle and make it obvious how to split them up after you're a bit more comfortable with the platform

they made a bunch of other obvious blunders like attempting to force real names and spread them to youtube, mandatory account linkage etc etc but i think there were probably just too many conflicting high level voices at google trying to set direction