Where do you draw the line? GMail, Calendar, Drive, Contacts, YouTube, Google+, Android, Chrome, Voice, Hangouts? Should they all have different sign-ons?
Is Google forbidden from integrating signons for all future companies it acquires?
It is the unification of user profiles that is causing all the uproar.
Just to clarify, I am making a distinction between being able to sign into a Youtube profile with a Google account and forcing the same profile across all Google properties.
Judging from my preferences, and based on my (limited) anecdotes, it seems that users appreciate the convenience of single-signin solutions, as long as each property they are signing into has a profile that can be managed separately.
Forbidden, yes; held hostage by their users for all the free platforms they provide in exchange for all the theoretical dollars they generate in page views
It's the attempt to push Google+ on me that I dislike.