Javascript has mutable datatypes and weak typing by default - that makes it easier to write buggy code than making it harder to do so.

To write nice JS, you have to be disciplined and very cognizant of what you're doing. And then you have to deal with the rest of the ecosystem, which is massive and of varying quality.

I recently ran into mutable date types in momentJS, which is a frustrating gotcha - it's not flip the table lose your shit annoying, but it's simply a non-existent issue in other languages.