I disagree. Once the behaviour is documented, it's fine for this "sticky" tools to exist. I find stupid to have an OS that allows to write in the root folder without any special flag in the command and ... well ... this happens because I'm using a GUI and misclick from time to time. On Unix, when properly administered, this can't happen. No idea... I'm more comfortable with a keyboard only...
on a second thought, this behavior does makes some sense. although it is very undesirable to put the configuration in the root directory, there's valid reason to traverse outside of the workspace when searching for the config file, e.g. it is reasonable to put a config file at some common locations, something like ~/projects/.cargo/config.toml, ~/repositories/crates/.cargo/config.toml, etc.