Chrome Inspector network requests shows that it's a server 500 error, and it tries to call the Multi Sign-on URI even I didn't enable Multi Sign-on.
When I tried to delete my Google Plus service, the page[1] is just 404.
Looks like G+ isn't really a finished or proper tested product.
It's currently in a "field trial"[1]. If you're using it now then you are a tester, so complaining about a lack of testing a little nonsensical.
[1] https://sites.google.com/a/pressatgoogle.com/google-plus/fie...
However, if in the course of the review, it becomes apparent that other Google Terms of Service have been violated, such as the 13+ age requirement (and you can thank Slimeball Politicians and Legislators all over the world saying, "Think of the children" for that one), the entire Google account might get suspended.