In his letter Edward Zuma said under normal circumstances his father's repayment of non-security upgrades to his Nkandla homestead would be "heralded the full and final end to the matter".
"When President Zuma paid the R7.8m amount relating to the non-security upgrades, true to form, the Nkandla matter received a new currency, instead of being received and perceived as a fossil that it is objectively. Under normal circumstances, the payment would have heralded the full and final end to the matter as a lucrative media source."
Taking jabs at the media, Edward Zuma said his father's repayment had instead been turned into an opportunity to flog a dead horse with many asking questions about affordability and other criteria.
"Others escalated their desperation to demanding proof of payment to be made available publicly. This is the kind of poor mental application and selective moral righteousness visited upon our country."
Edward Zuma said commercial media headlines have become a "cardinal path which drives and hegemonises all conversations of the socio-economic life of South Africa".
EFF to seek clarity
"What defies logic is the fact that citizens have allowed themselves to collapse under the weight of media collusion; making them pliable fodders for what in any credible thought is brave-faced propaganda."
This comes after a News24 report earlier this week that the EFF and the DA wanted President Zuma to provide proof of payment.
DA leader Mmusi Maimane was reported as saying it was important for President Zuma to provide proof to the National Assembly that he personally paid the outstanding amount and that claims that he had received a loan from the VBS Mutual Bank were not a front.
The EFF further indicated that it would seek further clarity on the main source and principle that led to VBS Mutual Bank granting a loan to the president. The party claims the bank is supposed to benefit ordinary people in Vhembe.
On Monday the Presidency confirmed that Zuma had paid the amount with funds raised through a home loan from VBS Mutual Bank.
National Treasury in June submitted a report to the Constitutional Court on how much he had to pay after the court in a March 31 judgment ordered Treasury to determine a "reasonable amount".
The costs included upgrades to a so-called "firepool", amphitheatre and kraal at his private Nkandla residence.