Users (and this is what the blog's author is here, they aren't developing Firefox they just want a benchmark activity) aren't very interested in solving technical problems and so, as seen here, they won't tell you what the error was. They definitely won't admit to any suspicion that it's in any way their fault. It's your fault.

From their perspective, who cares what the error is? They formed an intent, and then your stupid computer software instead of fulfilling their intent did something else. This is your fault.

For example maybe I wanted to delete the old data, and I typed "rm new-data". Don't tell me that deletes the new data, I can see that now, it's your fault that the new data is deleted, I wanted to delete the old data.

For a UX point of view, where possible try to offer "Undo". The user doesn't care that shooting themselves in the face was a bad idea, and they definitely don't care that you made them click "Yes, really, in my face, I understand this will hurt" three times first, now that they've done it, and it hurts, they want to undo it. Adding a forth confirmation step will not reduce the complaints.

Sometimes it will be hard to "undo". But you should periodically revisit decisions about that over the lifetime of a piece of software as resources increase. If you have 64KB bytes of RAM it's understandable if I can't undo "fill circle" in v1 of your Freeware art program. It's much less understandable in version 16 of the $100 program on a 16GB PC...

Would it make sense to be able to "undo" a Rustup even though that's difficult? Maybe. It's worth at least considering.

And yes, it is nice that Rust has a helpful community who might try to help you fix problems if you explain what the problem is, but this isn't really about Rust, it's about Users.