I've spent at least 15 years in enterprise companies and most new projects I've seen have been Scala/Clojure/Java 8 style in microservices form. Less so the monolithic WAR style apps.
Not dismissing the choice at all. Would just like to hear more about why they are bucking the popular trend.
I'm seeing this a lot. If you browse the site the article's on you'll find some more examples.
The moral of the story is that "we" all think Java EE is very enterprisey and that it's anti the popular trend (which is AngularJS, Node.js, or were those popular yesterday?), and meanwhile a couple of startups are being very productive and able to start quickly with modern Java EE because "nobody" has realy noticed that Java EE slimmed down so much and got so much more productive.
There are probably more java EE jobs out there than ruby ones. (It doesn't say anything really, except the fact that some places don't laugh at you if you suggest Java EE, some places would laugh at you if you suggest anything else)