Why it is important to know the difference between statically and dynamically typed languages? If one writes in only one of those (or one set) it is not important to him/her and doesn't specifically make him/her a worse programmer in that particular language.
Knowing a cursory difference between a statically and dynamically typed language in this day in age is not an unreasonable requirement for many developer positions, especially web development where you're often using a mix of languages.
As always, this sort of question is a test of competence by proxy and there are usually outliers, but statistically speaking, I think you'll find a very high correlation between inept programmers and people who don't know the difference.
If they didn't know it, I'd want to dig down into whether the understand the specifics of their particular language at least.
I actually just sat down in a meeting with a dozen programmers, some of them with decades of experience, and half of them didn't know what functional programming was.
General domain knowledge. We do Scala and a little bit of Python here and there. You should know the difference to show you're well rounded. Senior devs sound have some experience in both types.
I have a follow up question, "What are the advantages of a dynamically typed language over a statically typed one?"
This one kinda exposes the "Java-zellot" side of programming. If you love Scala and you're applying for Scala position, you don't often think like this. Being able to think critically about the things that are harder in Scala, that would be easier in a language without strict type checking, is a another good way to gauge if people can think critically.
