When you apply for a job why do they do a credit check?

Yes you are right its kind of a vicious circle that one gets trapped into and from which one needs to come out to secure a future for himself. Its kinda absurd only that one need to have a sound financial background to have a job because it might be that someone is seeking the job for the very reason itself.Company go for these credit check to prevent itself from being tricked by a fraud or someone like that but it then looses a potential brilliant employee. My suggestion for this would be that instead of the company looking at the current financial position of the prospective employee the companies should look into the potential earning capacity of the employee and then take its decision accordingly.