I suspect they'll soon have an issue where someone wanted to get fired but it didn't work...
Interesting point. In naming it this way, the maintainers have committed to firing anyone who uses it, as an implicit guarantee of the public-facing API.
Fortunately they're free to rename it in their next release.
Perhaps something snappy like __secret_internals_do_not_use_or_version_specific_retribution_will_follow_possibly_including_firing