Exactly, it is silly to consider Erlang a "pet language", it is an industry hardened language designed for the a near cousin to problem domain of WhatsApp. 20+

Exactly, it is silly to consider Erlang a "pet language", it is an industry hardened language designed for the a near cousin to problem domain of WhatsApp. 20+ years routing billions of calls a day under soft real-time, high reliability requirements... because you simply expect your phone to work, even phone calls from one end of the world to the other.