You are actually arguing for mediocrity. If someone needs to protect their employment by making their work more obscure so they won't be replaced then they probably aren't a very good hire. Companies tend to want to retain highly competent talent - not mediocre people or incompetents.

I'm definitely not arguing for mediocrity since I'm not arguing for obscure code. I'm saying that companies that have much turnover (which a lot of software companies have) won't choose a language that doesn't offer them a huge pool of programmers.

I think most shops that are run by people who have experience with software development will tend to choose languages that are fairly mainstream. Yes, the recruitment pool is bigger, but so is the entire ecosystem. Tooling, libraries, books, documentation, easy to find knowledge, long term committments etc.

There are few things that are more frustrating than working on something that so few people work on your search results when looking for solutions to problems come up nearly blank.

And despite what high thoughts we programmers have of ourselves: we spend an inordinate amount of time Googling things :-)