Why did the martyrs cry out for vengeance on those who persecuted them (Rev. 6:10)?

St. Augustine says, “as we read in the Apocalypse of John of the martyrs praying that they may be avenged (Rev. 6:10); while the well-known first martyr prayed that those who stoned him should be pardoned … the dominion of sin is destroyed and overthrown, partly by the amendment of men, so that the flesh is brought under subjection to the spirit; partly by the condemnation of those who persevere in sin, so that they are righteously disposed of in such a way that they cannot be troublesome to the righteous who reign with Christ … And they who pray for this, on the one hand pray for their enemies who are curable, and on the other hand do not pray against those who have chosen to be incurable.”⁹³