I know this change already took place some months ago, but I wanted to write about this now. Here's the situation:

* When I click on ![log In page](https://i.sstatic.net/9xJvp.png)
* I login on my Gmail account and get :![Google profile dialog](https://i.sstatic.net/QWIkk.png)![](https://i.sstatic.net/6SLxg.png)![](https://i.sstatic.net/JYR2K.png)but in my case, if I click on<kbd>Accept</kbd> then I'm forced to upgrade to a Google profile because of the new Stack Exchange OpenId login behaviour.
* If click on<kbd>Annuler</kbd>*(cancel)* I get :![the openid login fails](https://i.sstatic.net/a42Ea.png)

I created a Gmail account in the early beginning, I only had to fill in the password, name, and email address. I also find unfair that others providers don't have to provide this information while it is required for Google.  
I can understand this for things like Facebook... But, not every ***Google account*** is a ***Google profile***...

Also, let's be clear: 

* No, **I will never upgrade, the same way I would never create a social media profile**.

* **Do not try to convince me it's Google**, because the message states the contrary and it perfectly work if I login using those other ways :![stackexchange.com login page](https://i.sstatic.net/8u6lW.png)![meta.stackexchange.com login page](https://i.sstatic.net/0vM1i.png)

## **Update:**
Ok, you are not using OpenId but Google+ Sign in *(which is not really OAuth 2.0)*. [According to the documentation](https://developers.google.com/+/api/auth-migration#sign-in), there are two endpoints, and using https://www.googleapis.com/auth/plus.login instead of https://www.googleapis.com/auth/profile prompt users to upgrade to a Google+ profile even if you only require an email address.  
***Anyway*** Google clearly states it : ["Your app can either prompt those users to create a Google+ profile or not..."](https://developers.google.com/+/api/auth-migration#sign-in), which means that Google requires you to upgrade to a Google profile only if requested *(I don't really know who to believe but I'm open to [discussing it](https://code.google.com/p/google-plus-platform/))*.