I'm yet to verify this, but it seems that Rust is closer to Haskell in that it intends to enhance the likeliness of program correctness as it's being written and not only through testing. In go you still get runtime errors and I don't think it's all that rare, Rust should reduce those greatly.
I do share that adoption through libraries and widespread acceptance is very important and when you compare Rust to Haskell you make a nice point, the language could be great but not generate adoption.
However besides adoption I don't see anyone who seem to dislike the process of writing Rust itself. Apparently people think it's viable if more libraries are out there. The natural presentation of the arguments made me feel that people are open to it should the right libraries be there.
As for moving from Ruby to Rust or Go, Go is almost guaranteed to be faster for developers to learn. The reason for the complaints in the article is that Go is intentionally simple, and you're seeing many people migrating from dynamic languages to Go for those benefits. The fact that Go has its roots in C will make it immediately understandable to anyone with experience in a C-type language.
My final thought is going to address libraries and widespread acceptance. Regardless of your thoughts about Go as a language, there is no doubt it is here to stay. Underlying major technologies like Docker, it has already seen massive adoption. While initial signs are positive for Rust, you're still betting that it continues to build momentum and doesn't stagnate like Haskell.