One could ask why relatives or other company personnell are not permitted to fly as passengers on freighter aircraft.
The answer, of course, is well known: We pack these things so full of CAO freight and Lithium Batteries that no non-essential crew should be onboard. Period. Look no further than UPS or Asiana for the potential consequences.
Yet, we see our collegues rostered for 20-30 hours of PXing onboard the same aircraft, over 2 or even 3 transit stops, only to save the company from purchasing a DT ticket. Don't remember the GMA putting that in the old 'pros and cons' list of PXing on the freighter.
How's that for "caring employer of the decade".....