Same but for a different reason. Being able to overcome the learning curve and become comfortable using power tools to achieve equivalent results makes you a valuable employee as a human, it raises you to a higher level of control and increases your capabilities beyond what you could do with bare hands. (The only benefit of being capable without power tools is if there's no electricity for example. IANAC)
The same with "easy"/mainstream languages: something like OCaml/Haskell/Nim/Nix/etc. is a power tool with a steeper learning curve compared to something like Python/JavaScript/shell scripting; you being able (and willing) to handle it without abundance of learning resources says something about your mental capacity and potential value as an employee.
This is like one (non tech) company that I was hired at as a dev lead where they were about to embark on writing an “address validation module”. I quickly put an end to the entire project and worked with a vendor to license CASS software.
Companies pay employees to add business value. Not to get into their own flights of fancy to do things the hard way. As you mature, you learn only to focus on things that “make the beer taste better”.
I have yet to see an argument by any of the proponents of “obscure” languages where their choice adds business value.
And the “hard problems” that are being solved by the large companies at a scale that has never been solved are doing so by using mainstream languages.
I’ve never seen a report of a job interview where they asked you to reverse a binary tree in Erlang.
The vast majority of problems that developers are being asked to solve are not that hard technically. They are business problems.
I mean more having learned to be productive in an obscure language as a positive marker regarding your mental capacity, intrinsic motivation, autonomy and initiative. If you then insist on using it for everything, business value be damned, that is a red flag. Choosing an obscure language to tickle your fancy would be negative value to me as a business owner since I need to hire and maintain a team of developers who are all comfortable and proficient in it. However, there are circumstances in which an obscure language might just be the right tool for the job (and overall architecture that can accommodate a small cohesive component written in a different language has its benefits).
You think it’s a red flag for a business to hire people who can add business value?
I’m motivated to get up everyday for the same reason most people are - money.
I bet you’re looking for people with “passion” and who are willing to consistently put in more than 40 hours a week aren’t you? Out of all the millions of things I can do and have done in my free time over my career (including a working hobby as a part time fitness instructor back in my younger days an avid runner and a weightlifter) spending more time sitting at a computer outside of work isn’t one of them.
And the obscure language would hardly ever outweigh the need to recruit developers easily.
> You think it’s a red flag for a business to hire people who can add business value?
Where have you seen that?
> I’m motivated to get up everyday for the same reason most people are - money.
You are quite mistaken. Once they have enough to exist comfortably, people tend to seek meaning not money. The emergence of OSS ecosystem is the best example -- a lot of it, including the most popular OS in the world, came about as hobby projects people did in their spare time. If you're a software engineer, I bet you use products of their passion a lot in your money-making activities.
> I bet you’re looking for people with “passion” and who are willing to consistently put in more than 40 hours a week aren’t you?
Again, all else equal, if I need to make a decision as to who would be a better, more capable employee in absence of other information, the one who managed to be productive in an obscure language would be higher on my list. Just that. Everything else, making people work overtime, etc., is your addition.
The same with "easy"/mainstream languages: something like OCaml/Haskell/Nim/Nix/etc. is a power tool with a steeper learning curve compared to something like Python/JavaScript/shell scripting; you being able (and willing) to handle it without abundance of learning resources says something about your mental capacity and potential value as an employee.