Expensive effort to insult someone. Papyrus wasn’t cheap.
“...Expensive effort...”
He was pissed off... Anger has a deep wallet...
Most people wrote their correspondence on ostraca (broken pieces of pottery) then found someone who was heading in the right general direction to carry the message to their distant beloved or whomever. Probably this Oxyrhynchus papyrus heap came from the Byzantine era version of the NSA. :^)