Enforcement of Federal standards through Federal inspectors would result in the most intimate involvement of the Secretary of Labor in all operations affecting interstate commerce….easily result[ing] in blowing up the most minor grievances to very substantial proportions. A minor complaint can very well become a ‘federal case’. Provision of this kind of authority in the Federal government would tempt many an employee representative to boost his stock by calling on the federal government, since the very presence of a federal inspector could be used to demonstrate his importance and influence.