I suppose my views are skewed because I have become competent or better in a large number of languages. I have my favorite general-purpose language, of course (it's C++-as-a-better-C), but I view choosing a language for a particular project to be an engineering decision that I make according to the demands of the project, not based on what language I personally enjoy the most.

Developers do get emotionally invested in their tools, and I've seen an uncountable number of holy wars because of that. But all of them strike me as being ludicrous.

If another dev uses a language I would not have chosen, that's not a personal affront to me. I assume they made an engineering decision that made sense for their situation. It's all good.

> If it did, their language's viability is threatened and their investment is in jeopardy.

I sorta see this, but in my experience, it's very easy to overstate this case. If a language is viable enough to develop in initially, it's viable. How popular it is or becomes isn't really that important except in terms of being a business decision ("is it possible to hire people in the future who know this language?")