In any case, if people want other people to invest in "their language", they should focus on making that language and its ecosystem compelling to use, not bash other languages...
That said, in terms of language features and type system, Kotlin is arguably closer to Go than it is to Scala. Yes, Kotlin competes with Scala on the JVM, but it's a very different language. Scala is much closer to a language such as OCaml than it is to Kotlin.
However others who approach from position of authority like compiler hackers, language authors themselves, or very senior developers etc. Ideally criticism from them should be more valid but more often than not I have seen they keep making bad faith arguments and justify their hate by precise technical arguments so they can't be challenged by non-technical arguments. It makes vary of their arguments even on topics other than favorite programing language.
Thats somewhat by happenstance though isn't it; you take go, build a good enough scientific computing library, and tease out good enough performance, and get enough coworkers on it, and you'll probably have Go advertising itself as a scientific computing language (when talking to the relevant people).
And then you'll probably have go language devs implementing features better targetting the scientific computing community
And as the new people feed in, and implementing their own needs and libraries, suddenly go becomes good at ML...
And eventually we reach an 80s C-like status, advertised for nearly everything, because of its heavyweight ecosystem.
In terms of ecosystem, its really not constant for what they're good at. What might be constant is the flavour of programming the language prefers; you're probably not getting rid of goroutines as a significant language feature no matter how big Go gets.