If you have had to make a new Gmail account in recent years, you will have noticed that the service required you to sign up for Google Plus as well. This was just one of the many methods Google employed to make sure people would join its G+ service although whether that was a good idea or not is still up for debate (not really).
Thankfully, Google has been taking some steps to remove mandatory Google+ services from its ecosystem after all the hate the system got and email is their latest target. Users that want to create a new email address will no longer have to sign up for Google+ just to access their email as they will be taken directly to their inboxes.
Other services, like reviews, still require a G+ sign-up and that will probably not change any time soon. Regardless of the fact that this was a very annoying feature right from the beginning, it shows that Google is quite committed to their promises of making the Google ecosystem more pleasant to work with. Even if you like Google+, having it all up in your face all the time certainly does not make for an intuitive experience.