Here are two links that I found useful today:
Which developer do you think is going to be more productive? The dude having to know 3-4 different technologies, or the dude who just needs to know JS?
The developer that uses the right tool for the job will be more productive.
That means using a language with static type checking and a productive debug environment. Learning a new system infrastructure takes time, but only finding out about easily preventable failures during testing instead of compile time costs more.
"Conversion, fastidious Goddess, loves blood better than brick, and feasts most subtly on the human will." -- Virginia Woolf, "Mrs. Dalloway"