Well, people who can write in less popular languages are definitely above average programmers. But I think it just mean they can write code in their own instead

Well, people who can write in less popular languages are definitely above average programmers. But I think it just mean they can write code in their own instead of copy&pasting from the random web sites. Being a less popular languages means you can't find convenient example codes from the Internet. Still, being able to write code in their own doesn't mean they can write a good code. I witnessed a complex recursive code with a bug on edge case in a functional language. It could be easily and cleanly written by using common practice of that language and its standard library, like foldl. Also, code lives longer than you expected.