I don't consider Rhino nor other Javascript environments like Adobe Actionscript and Microsoft JScript as contributing to the "Javascript identity." It really seems like the Javascript apologia/evangelism was kicked off by Nodejs' popularity.
As a consequence, we see many "I'm leaving Nodejs for Go" and virtually zero "I'm leaving Rhino for Python".
http://steve-yegge.blogspot.com/2007/06/rhino-on-rails.html