They do get to decide which jobs they take. And the languages involved are one of the easiest filters. A lot easier than checking whether the code a company actually writes is any good.

Theoretically you don’t need to write AbstractFactoryProvider in Java, but looking at languages mentioned in job offers, I have a pretty good idea of which of them have a high probability of working with such code and which do not, even if all of them say they have the best code ever.