That was the strangest part for me. Google+ forced an odd hybrid between my personal and business activities, but it wasn't absolute. I couldn't tell you how many google interfaces I have right now, I'd have to count them and go through a few while logged in to make sure it was complete.

It wasn't that much work, but I suspect they could have improved their user testing on how multiple identities worked.

Maybe they were just targeting the median user, but that is likely a mistake if you miss all the evangelists.