"The position of the workers here is not new, neither is their argument, but you have never encountered it before?"
Of course I have. It hasn't made actual sense for a very long time, however.
"You seem to be implicitly assuming that the corporation will fight for their position, and that there is nothing wrong with that. When workers do the same suddenly you are left in shock and disgust. Why is that?"
Because the corporation is already competing for talent in the other direction (very much so in fact!), but when it's the workers that need to compete, their answer is to complain that their is competition?
"If Facebook wants to hire cheaper bus drivers, then they should just relocate to a cheaper area, right?"
Sure, this is a viable alternative to me as well.
Companies often do move when it becomes economically infeasible to stay where they are.