I understand that automatically signing in can be creepy for some users, but isn’t this just a problem of misunderstanding?

I mean, when the same user logs in to any of the service of the same suite, then he’s already giving information to access the suite, the same suite which contains all the seperate services he might use.

So, why not save him the hastle of having to log-in multiple times and use his decision to log-in to a service in a suite made global to all the services at once?