It's completely fine for someone working on a programming language that is useful for some of the same things as Rust to compare that language to Rust, including in ways that make the language not seem as good. Indeed, this is useful information for someone who is using Rust and is considering using Zig (or vice-versa), or who is new to both languages and trying to figure out which is better for their use case.
You seem to be running a lot of interference in this thread.
In what way is the tone of the linked messages appropriate?
In what way is the tone of the linked messages not appropriate? Rust is a programming language, not a sacred object. It's fine to say that a different programming language does something better than it, regardless of whether or not you're the developer of that language.
To be clear I like Rust and use it frequently and have for about as long as it's been publicly released, whereas I have only played around a little bit with Zig and I suspect I won't like it as much as Rust even when it's feature-complete. But I don't like seeing an attempt to enforce a social norm that it's wrong to point out shortcomings of Rust, especially when it's aimed at people doing the interesting and valuable work of exploring other areas of the systems programming language design space that Rust is not doing.
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