I've seen and heard this, (Data science field definitely loves their Python and numpy) but I really believe the common problem of non-reproducible research is partly due to the language choice (and probably more to the root cause - this sentiment in research).

I know you've listed the common argument for static vs dynamic (dynamic -> so fast to code but slow to run, static -> way too complicated)but after a decade in SE I still have yet to see some good evidence of this.

Yes some static languages (like Java) will make developing certain things slower vs JS but is Java a good statically typed language ? Maybe these statements are "true" today with the current implementation of one or the other but there are a lot of languages that I just can't see getting in the way.

A new example of this: Kotlin and Swift are statically typed and I would love love to see where it slows these mythical developers that are so fast in a dynamic language but would be slowed down using them. There's obviously going to be a cost for the actual compile time but that should be minimal.

Unfortunately I'm starting to believe that this is just another case of certain developers are used to certain languages.

The trend of the JS move to TS also points to this. Basically JS looks very similar to Kotlin and Swift (TS is basically identical).

To look at your specifics > Dynamic languages let you introspect and modify things way more easily, and this makes things like fakes and mocks for testing way easier. It makes debugging easier. And not having to wait an hour for something to compile is nice.

> Dynamic languages let you introspect and modify things way more easily

In what way ?

> and this makes things like fakes and mocks for testing way easier

Fwiw this is what that fake/mocks look like for a static language `val x = mock()`

To be fair that's using a library and maybe that's part of your criteria ?

> It makes debugging easier

? how, I can see the argument for the other way (one less thing the developer has to worry about - typing issues) but how is dynamic easier to debug ?

> having to wait an hour for something to compile is nice

Completely Fair. Now whether or not the thing you're working on would take an hour to compile I highly doubt. If you're working on a project that would hypothetically take an hour to compile then I really hope it's not written in a dynamic language.

Not trying to pick on you at all, I believe a lot of developers would agree with you but I'm starting to think that there are developers that are just used to one or the other. I have to point out that I could be thinking this way with respect to statically typed languages but I really have a hard time seeing this point (as I would be if I was falling into the same trap I'm "accusing" you of).