I've worked in startups that tried to implement the "1-2 languages only" (usually Java and Jython/JRuby/Groovy) policy as a startup, and they didn't go anywhere. That team of prima donnas who is willing to mortgage the startup's future in order to ship an awesome product seems to be a necessary feature of startup success, and only successful startups get to hire the team of professionals who will button down everything, choose "official" languages, and build tier-1 infrastructure. So yes, it's incredibly unfortunate, but this is the industry we live in. Pick which role you wish to occupy accordingly.
I believe those 4 languages were Java, C++, Javascript, and Python. Nowadays they also use Go, Dart, Groovy (in Android Studio), and I guess a lot more. (When I say Groovy, I mean the tiny non-Turing Complete subset of the syntax used as a DSL in typical Gradle build scripts.)