I wouldn't see the issue here if the employer was willing to "pay handsomely" to have their employees work those hours. Some white collar workers work those hours every week - if not longer - and are paid well for it.
It is, indeed, fascinating how little respect workers have for each other. Any little concession they can offer an employer to screw over the guy beside them, they will take it.
Unionization helps develop somewhat of a brotherhood to keep the nastiness at bay, but even then the members generally want to keep it an exclusive club, not something for all workers to join. As a result even union members still see external pressure from the workers outside of the union still trying to them screw over.
Actually I'd prefer OSHA set some sane limits on hours worked instead of assuming an Invisible Hand will stop employers from working laborers to death.