According to St. Jerome, noble Romans have become complacent and corrupt.
Step-by-step explanation:
The time when St Jerome was writing in was the time of decadence of Rome as a power and it was in imminence of a downfall at the hand of the tribes up ahead of Rome.
This is what was one of the primary concerns of that happening according to St Jerome.
The people of the nation had become complacent and self serving.
They had not been thinking of the nation the way the founders of the Great Empire of Rome did.
This is what St Jerome resents in his account.