This Adsense user has been resisting the push for a Google+ account.
In the past, the sign-up page required BOTH email address and birthday.
I see that they have now dropped the email requirement from their sign-up page. I guess they finally realized that those of us who have had to deal with over 100 spam emails a day, do NOT want their email address publicly displayed who knows where. Currently, my email address is given only in a graphic. These days, considering the harvesters, creating a live link to your email address is pure lunacy.
Now, if I can just submit a phony birthday, all will be well, and I will finally sign-up, without fear that my REAL birthday will be broadcast to identity thieves. Google shouldn't even HAVE my birthday data. I would like to see my "author" stats in GWT, which requires a profile, whereas using the Google +button does not.
I am probably going to sign up, using a phony birthday.
There is no way I will ever use Gmail.