The Lord repeatedly sent messengers -- prophets -- to the Jaredites to warn them to repent or be destroyed. They ignored the warning or persecuted the messengers.
20 And in the days of Coriantor there also came many prophets, and prophesied of great and marvelous things, and cried repentance unto the people, and except they should repent the Lord God would execute judgment against them to their utter destruction;
21 And that the Lord God would send or bring forth another people to possess the land, by his power, after the manner by which he brought their fathers.
22 And they did reject all the words of the prophets
Words of warning from a loving Lord had no effect on them except to anger them. The one reference in this chapter to repentance notes a different source:
7 And they hearkened not unto the voice of the Lord, because of their wicked combinations; wherefore, there began to be wars and contentions in all the land, and also many famines and pestilences, insomuch that there was a great destruction, such an one as never had been known upon the face of the earth; and all this came to pass in the days of Shiblom.
8 And the people began to repent of their iniquity; and inasmuch as they did the Lord did have mercy on them.
People of faith hearken to the prophets and apostles and follow the teachings of Jesus. They repent because they love God. Those whose hearts are hard are condemned to learn the hard lessons that flow from the consequences of their own choices.