Reposting same jobs, revolving recruitment

I am always wary of companies who seem to never fill their positions but post and repost the same jobs over and over. There are a few in the Lehigh Valley, and this employer is one.

There must be a reason why they never fill the positions. I think one reason might be that they have to satisfy the federal govt. For instance, the govt gives the company free money ( a grant ) and in return the company promises to create jobs. The company really doesn't want to add jobs nor do they need to but they want the money - so to keep the federal government from taking the money back they show all the job postings and resumes that they have accumulated and tell the govt that they are trying to add jobs but they can't find qualified candidates to fill them. There must be a some reason because I can't believe that they can't fill a particular position after 4 to 6 months. It is extremely frustrating to send out resumes ( it takes hours to prepare the perfect cover letter and resume ) to companies like Uline.