This is also why Facebook has spent so much time and effort on things like HHVM and Hack.
This is also why Facebook has spent so much time and effort on things like HHVM and Hack.
* Would you hire somebody who wasn't able to learn a new language in a reasonable amount of time?
* Would you let somebody who just started with PHP (by virtue of it being an easy language to start with) work on your backend?
A good developer will learn a new language in a reasonable amount of time and will be able to be productive and write good code in it.
A PHP-only (or X-only for that matter) developer is, by the definition above, not a good developer.
So why restrict oneself to some random pool of X-only people?
FWIW, they have released cool open source projects on Haskell and ocaml, so it's not like they've never considered any alternatives.
I also have a small suspicion that they wanted to stick to their roots a bit. But thats just me.
In many cases the latter forces you to compromises in what you pick and the first one in compromises when you pick it.
I fully understand when people try to make work what they have.
Eg PHP by itself is a very fast powerful language. The tooling and several aspects (dynamic type etc) are exhausting for larger code bases but this is something which people inhouse can solve without requesting the full company to switch.