It's funny I used to get that screen to turn it into a plus account but I got annoyed with it and opted out, I guess I didn't appreciate it was a one time option. All I get now is a plain profile picker (which as I say defaults to the social network profile, I have accidentally used it several times liking videos etc and then realising I was in the wrong profile). All things being considered this is only a trivial annoyance, I am just surprised at how bad the UX is for me now.