When you try to open an email, the last thing you want is to end up having a personal profile associated with it. Many people even have several emails, and if they are using Gmail that means they should also have several Google+ profiles!
It is annoying without a doubt, and it is one of the inflation factors of the Google+ user base, but now that Google is no longer focusing on it’s social network, the mandatory Google+
Gmail Integration might be hurting Gmail growth , a growth that was once sacrificed in order to make Google+ stronger, but now as Google’s social networks slides into the less important projects, Gmail sacrifice was no longer needed (see picture below)! Thus any new Gmail user can opt for not creating a Google profile at all … unless they decide to upload a video on Youtube or leave a review for a business.
According to a Google spokesman:
“We updated the signup experience in early September. Users can now create a public profile during signup, or later, if and when they share public content for the first time (like a restaurant review, YouTube video or Google+ post).”