I am not sure which way to argue, I see danger in both lack of protections and too many of them. Middle road is required
> this has already been the case since before the the Great Depression.
the solution was, unfortunately, majority of Yidden not keeping shabbos, so we do need some protections, but not entitlements.
A private business should have a right to run the business the way they want. If managing someone with shabbos observance is a tircha for them, we should not demand being hired.