A Google spokesperson confirmed the change to Quartz: "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)."
Google has removed the "real names" policy and made Hangouts available to Google Apps users who don't have Google+ accounts. It's likely that Hangouts and Google Photos will become standalone apps that don't require Google+. As Google+ fades into the background, it's time to open Google's apps to everyone and transform Google+ into a social enhancement instead of a requirement.
Back in 2012, creating a Google account from the Google homepage meant joining Gmail and Google+. Some time ago, Google added the option to use an existing email address and now you can bypass Google+.