It seems like they're being pragmatic, not haughty:
> "The tz database is not authoritative, and it surely has errors. [...] Errors in the tz database arise from many sources: Sometimes, different people in the same city maintain clocks that differ significantly. [...] Even if the time is specified by law, locations sometimes deliberately flout the law. [...] Any attempt to pass the tz database off as the definition of time should be unacceptable to anybody who cares about the facts."
> "The tz database is not authoritative, and it surely has errors. [...] Errors in the tz database arise from many sources: Sometimes, different people in the same city maintain clocks that differ significantly. [...] Even if the time is specified by law, locations sometimes deliberately flout the law. [...] Any attempt to pass the tz database off as the definition of time should be unacceptable to anybody who cares about the facts."
https://data.iana.org/time-zones/theory.html#accuracy