To drop shunning would mean no longer being authoritaians, the whole structure would crumble because they have reached a point of no return they must stay the course till they go belly up.
https://en.wikipedia.org/wiki/Criticism_of_Jehovah%27s_Witnesses
Social criticisms[edit]
Authoritarianism and denial of free speech[edit]
Doctrines of Jehovah's Witnesses are established by the Governing Body,[148][149] and the denomination does not tolerate dissent over doctrines and practices.[4][150][151] Members who openly disagree with the movement's teachings are expelled and shunned.[152] Witness publications strongly discourage followers from questioning doctrine and counsel received from the Governing Body, reasoning that it is to be trusted as part of "God's organization".[151][153][154][155] They also warn members to "avoid independent thinking", claiming such thinking "was introduced by Satan the Devil"[156][157] and would "cause division".[158] Those who openly disagree with official teachings are condemned as "apostates" who are "mentally diseased".[159][160][161]
Former Governing Body member Raymond Franz has accused the movement's Governing Body of resenting, deprecating and seeking to silence alternative viewpoints within the organization[162] and demanding organizational conformity that overrides personal conscience.[163] He claimed the Watch Tower Society confirmed its position when, in a 1954 court case in Scotland, Watch Tower Society legal counsel Hayden C. Covington said of Jehovah's Witnesses: "We must have unity ... unity at all costs".[164] He also stated that Witnesses are subject to a disciplinary system that encourages informants.[165][166]