It isn't true. By default -- including on a brand-new Nexus 4 -- it will notify you that photos are ready to be uploaded, and if you follow-through it gives you the option of automatically uploading from then forward.
That's the same way malware/toolbars get installed...
1. buy new note2 from att, register google account, skip samsung and att setup.
2. buy new s3 from amazon unlocked, register google account, skip samsung setup.
3. never even open G+ app on both phones
4. take a picture
5. wait an hour
6. you get a notification "pictures you took are ready for sharing" i.e. they are already uploaded against your will and out of your knowledge.If someone complain about a bad Android default or behavior in a non nexus device, and you have a nexus device, just stay put!
Nexus are a completely different beat when it comes to user control, ok?