I'll gladly steelman the opposite idea. If you're running a McDonalds and you fire half your employees to replace them with burger-flipping robots, you damn well better expect the cashier to quit or go on strike. People aren't that stupid - they can see the Looney-Tunes ACME anvil suspended over their heads, they know when they have to negotiate themselves off the red painted 'X'.

Similarly, I think introducing automation to a historically-human career like longshoring is absolutely an all-or-nothing shtick. You're either displacing your human workers entirely with unpaid alternatives, or you're dealing with the consequences of a partially human workforce. There is no magic compromise, despite what management wants. You either acquiesce or replace them with robo-scabs.