[rpeden]

I don't think you deserve to be attacked for implying that about WhatsApp. You're right, in that the truth is that in the vast majority of cases for the vast majority of cases, programming language doesn't matter all that much.

Perhaps people disagreed with you because it seems to me that WhatsApp is an outlier where a specific language and runtime (Erlang & OTP) provided a clear advantage in a specific domain (realtime networked messaging). In this specific instance, the language provided facilities that made it easier to solve a specific type of problem than it would have been in other languages. It helped them get to market more quickly, and in that way could have directly contributed to the application's chance of success. I suppose what I'm getting at is that I think there's a decent case to be made that WhatsApp is one of those very specific instances you mentioned where the language is part of the company's secret sauce.

That's still no reason for anyone to attack you, though! It's easy enough to disagree in a friendly way. :)