Jaynes on the Nabiim

What happened to them? From time to time, they were hunted down and exterminated like unwanted animals. Such a massacre in the ninth century B.C. seems to be referred to in I Kings 18:4, where out of some unknown, much larger number, Obadiah took a hundred nabiim and hid them in caves, and brought them bread and water until the massacre was over. Another such massacre is organized by Elijah a few years later (I Kings 18:40).

We hear no more of these bicameral groups thereafter. What remained for a few centuries more are the individual nabiim, men whose voices do not need the group support of other hallucinating men, men who can be partly subjective and yet still hear the bicameral voice. These are the famous nabiim whose bicameral messages we have already selectively touched upon: Amos, the gatherer of sycamore fruit, Jeremiah, staggering under his yoke from village to village, Ezekiel with his visions of lofty thrones on wheels moving through the clouds, the several nabiim whose religious agonies are ascribed to Isaiah. These of course merely represent the handful of that much larger number whose bicameral voices seemed to be most consistent with Deuteronomy. And then the voices are as a rule no longer actually heard.

In their place is the considered subjective thought of moral teachers. Men still dreamed visions and heard dark speech perhaps. But Ecclesiastes and Ezra seek wisdom, not a god. They study the law. They do not roam out into the wilderness “inquiring of Yahweh.” By 400 B.C., bicameral prophecy is dead. “The nabiim shall be ashamed everyone of his visions.” If parents catch their children naba-ing or in dialogue with bicameral voices, they are to kill them on the spot (Zechariah 13, 3–4).8 That is a severe injunction. If it was carried out, it is an evolutionary selection which helped move the gene pool of humanity toward subjectivity.

In other words, it's possible that in stable times, prophets are killed, but in uncertain times, they are consulted. See The necessity of "degenerates".

From Human Sacrifice:

Human sacrifice may be a ritual practiced in a stable society, and may even be conducive to enhance societal bonds (see: Sociology of religion), both by creating a bond unifying the sacrificing community, and in combining human sacrifice and capital punishment, by removing individuals that have a negative effect on societal stability (criminals, religious heretics, foreign slaves or prisoners of war). However, outside of civil religion, human sacrifice may also result in outbursts of blood frenzy and mass killings that destabilize society. The bursts of society-sanctioned killings during European witch-hunts,[8] or during the French Revolutionary Reign of Terror, may show similar sociological patterns (see also Moral panic).