Source

In a nutshell Trump had many of his appointees exempted from paying Social Security taxes. He promised them Congress would forgive the debt. Apparently he sent that memo out to many business. Most declined for this very reason (below.)
Congress didn’t forgive the debt, and now the IRS is hounding these people, giving them 30 days to pay the past due taxes or face dire consequences.
Many of them feel betrayed.
(BTW. Even if Trump instructed payroll to eliminate the tax, the workers could have paid the tax themselves.)