Yup this is an interesting specific case of a more general political problem: at what point does legitimate individual concern, when applied to a collective, cause problems to an even greater collective. We see it in things like pandemic response, monetary policy, and this labor issue.
Consider a contrived example: What would happen if every single supplier of insulin, say, just decided they didn't want to make it any more. Would people accept the government forcing people to work to make it? Even if the government took imminent domain of the facilities, and offered massive salaries to people to take it over, there would be a ramp-up gap to train the new people. Could the government force the workers that wanted to leave, to keep making the product so there wouldn't be a literally deadly shortage in the interim before the ramp-up time was complete? Whose "rights" win here - the bodily autonomy of the workers, or the "right" of people needing the product to have it? (This is intentionally worded to be as argumentative as possible, by the way...)
What happens in the reductio ad absurdum where even with offering stupidly high wages, they don't get enough people to operate the insulin factories, so there isn't any supply anyway?
I do see the rail operators' concern with this - sure they can give individuals lots of sick time. But if they do get too many people simultaneously using sick time - that's a problem, and it likely can't mathematically be solved just by hiring more people: after all, if they keep increasing wages and people still aren't accepting jobs (as hinted by the earlier post), what happens. Can we "force" companies to be unstable by over-hiring and having smaller profit margins? Sure companies may have record profits today, but if they aren't saving some of it, then any disruption will cause problems - this isn't even a question, we have numerous examples of what happens when companies have no reserves.
Now personally I think society as a whole would be better if it shifted more of its focus to sustainability rather than growth, but the incentive structure is heavily weighted to growth. This isn't just Wall Street either - it's in many people's personal view too; not satisfied simply with current standard of living, always wanting increase either now or in their retirement accounts.