a) It's not only Labour who have centralised power thus - remember threats of deselection are not privy to themSo. I read a piece recently by David Graeber about the Labour Party and anti-Semitism.
It argues that the basic reason the Parliamentary Labour Party hates Jeremy Corbyn is that Corbyn and his followers have been trying to democratize the Labour Party internally- create something similar to a US primary system so that MPs are actually answerable to their constituencies from time to time. He claims that under Blair the MPs were basically set up as MPs for life, and the underlying reason for their hostility to Corbyn is that the reforms to the Labour Party he is trying to carry out directly threaten their careers.
Does anyone have any comment on this? I am not familiar enough with Labour Party history etc. to judge, obviously, but it seems pretty plausible to me.
b) it's a damagingly outdated system now that there's been fixed terms and other reforms enacted since then 1990s.