That's an unfortunate stance on Groovy. Groovy code is often far more brief than Java's, and it has some beautifully expressive capability for making DSLs, both through its world-view on closures and its ability for the developer to walk and modify the AST at compile time (see, for example, the @Canonical attribute for how this can be useful)

While I, too, wish it built on a statically typed base, Groovy offers amenities such as @CompileStatic that go a long way towards alleviating this.

I personally find Kotlin strikes a wonderful spot with the brevity and expressiveness of Groovy, while managing to be more type-safe than Java (reified generics, null safety in the type system). But there is no denying Groovy's heavy influence on Kotlin, either.

Groovy may not be perfect but I don't think the picture you paint is accurate, either.