There should be a maximum working hours, although it should be higher than most people will work. Right now most people work about 40 or 50 hours per week, however many are paid salary, and work way too many hours, and it just isn't fair. More than a fairness issue however, this is a safety and health concern.
The manipulation of the work week by the federal government is already a failure. Forcing overtime for certain employees entrenches a class system within a workplace, it interferes with the voluntary relationship between employer and employer, and it is an example of the federal government overreaching its mandate. Making a maximum work week would force more employers to look to part-time employment to fill work gaps, above and beyond what is already in place because of past insurance being tied to employment and the future Obamcare extension of that.