Every language would do us (programmers) a great favor by having a page titled "Pro & Cons" or even "When to use X / When not to use X", and could include comparing other languages as well. Maybe it's hard to sell your language if you have to include cons/when not to use X as well, but it'll help gain trust for sure.
In the case of Hare, it doesn't seem to be good if you want to be able to have anything running on Windows/macOS, as one stated goal is "Hare does not, and will not, support any proprietary operating systems" according to https://harelang.org/platforms/, which makes it very unattractive for me at least, as I move across three platforms daily.
In Hare's defense, not every programming language needs to target every runtime/OS/environment.
JavaScript only targets the browser. Shaders usually targets one graphic runtime. Maybe there is a space for a language that just targets a few OSes, or even just one? Remember that both C# and Swift initially just targeted one platform, so maybe it does makes sense to now have one OSS language for OSS nerds.
While that was true for years, Node.js has made JavaScript viable on the server for quite a while. But I agree with your overall point. I think JS and C# are good examples of languages that were seen as valuable enough to start using in other environments. I love C#.
Well, naturally, with people who use the other one: Arduino. I mean FreeBSD. Or maybe FreeRTOS? Wait, Android. Or NetBSD. Or Wasm. Or JS. Or the JVM. Or the .NET CIL. Or ReactOS. Or SerenityOS. Or FreeDOS. Or Illumos. Or OpenSolaris, heh.
Or just regular old GNU/Linux like 70% of the Web. But either Android installs or FreeRTOS installs easily outnumber those.
In the case of Hare, it doesn't seem to be good if you want to be able to have anything running on Windows/macOS, as one stated goal is "Hare does not, and will not, support any proprietary operating systems" according to https://harelang.org/platforms/, which makes it very unattractive for me at least, as I move across three platforms daily.