>In 2009, virtually nobody considered themselves a "Javascript programmer".
I'm guessing the "Javascript is my identity" era began with Nodejs. Before 2009, Javascript was something that was "tolerated" because it just came with all the browsers. Back then, having any point of pride in being a "Javascript programmer" would be a little weird as if a homeowner proclaimed he was a "Panasonic keypad microwave programmer instead of a Samsung microwave programmer". Nobody cares what buttons you press to pop your popcorn. Likewise, the "Javascript" stuff was just something you had to do for interactive webpages.
However, for someone to have the audacity of duplicating the Javascript environment on the server side... that means subsequent programmers get to make an invested choice, which means... flame wars.
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".
I'm guessing the "Javascript is my identity" era began with Nodejs. Before 2009, Javascript was something that was "tolerated" because it just came with all the browsers. Back then, having any point of pride in being a "Javascript programmer" would be a little weird as if a homeowner proclaimed he was a "Panasonic keypad microwave programmer instead of a Samsung microwave programmer". Nobody cares what buttons you press to pop your popcorn. Likewise, the "Javascript" stuff was just something you had to do for interactive webpages.
However, for someone to have the audacity of duplicating the Javascript environment on the server side... that means subsequent programmers get to make an invested choice, which means... flame wars.