[citation needed]
Honestly, Rails wasn't the first or last RAD platform and I don't think a randomly-selected subset of programmers who have used it would describe it as a shining beacon of light.
JS frameworks are actually pretty diverse, and if you think the ecosystem is a bunch of MV* variants just waiting for something innovative to come along, with respect, you just aren't familiar with what's out there.
Okay. The year is 2005. PHP5 was fresh out of the oven and most people were still on PHP4. From PHP's point of view, there's rumors of something happening in the Ruby community that will be big, and should be talked about [1].
Then Rails 1.0 drops at the end of the year. From this Slashdot thread [2] on the announcement you can gauge the contemporary reaction; comments detail the fact that Rails was breath of fresh air from the configuration-heavy Java frameworks of the day -- represented by Struts [3], but others weren't much different in this regard, as these books from 2002 and 2004 about alternatives to Struts show [4][5]. Several ASP developers, detail their positive experiences in switching their web development to Rails [6][7][8]. The PHP world is forever changed -- by 2006, frameworks inspired by Rails abound [9]. "Ruby on Rails" becomes a popular phrase, some frameworks borrow the naming scheme along with the ideas: "Groovy on Grails" [10] tries to bring Rails' ideas to the Java world, "PHP on Trax" (formerly "PHP on Rails" [9]), "ColdFusion on Wheels" [11].
I'd say Rails made quite the splash.
[1] https://blog.phpdeveloper.org/2005/12/31/25/ [2] https://developers.slashdot.org/story/05/12/14/0034219/ruby-... [3] http://weblog.rubyonrails.org/2005/2/22/comparing-struts-to-... [4] https://www.safaribooksonline.com/library/view/programming-j... [5] https://www.safaribooksonline.com/library/view/programming-j... [6] http://weblog.rubyonrails.org/2005/6/28/asp-net-vs-rails-ana... [7] http://weblog.rubyonrails.org/2005/12/20/neters-tell-scoble-... [8] http://weblog.rubyonrails.org/2005/7/5/not-knowing-where-it-... [9] https://h3rald.com/articles/rails-inspired-php-frameworks/ [10] http://grails.1312388.n4.nabble.com/Groovy-on-Rails-is-no-mo... [11] http://cfwheels.org/blog/how-oo-almost-destroyed-business/
The source you quote says "Groovy on Rails", which was the official name until it was contracted to "Grails" due to the insistence of the Rails crowd that "on Rails" not be used in any other product names. The "Groovy on Grails" phrase you wrote was a later unofficial but intended mispronunciation of the earlier name put out by the Grails crowd to make it sound like "Ruby on Rails" as a snipe at the Rails crowd. To those of us who thought Groovy would make a good language outside of its use in Grails, the mispronunciation made it sound like someone in the Grails crowd thought Groovy's only use was for scripting Grails.
Second, regardless of that, I think the JS ecosystem is well-enough explored that the chances that some single new idea or platform is going to dramatically change everything doesn't seem very likely to me. For reasons I've mentioned in my top-level comment on this page, I think diversity of the JS ecosystem is going to be with us for a while.