Required to File??

Client was owner and president of construction company that built residential homes. He retired in 2000 and no longer does any construction work or has any management responsibilities. The company still exists on paper and every year he's been filing Form 1120S and the equivalent State return. There are no employees, no "office," no revenue and the only expenses are the couple of hundred bucks he dutifully pays every year for a local county business license. Both returns contain only identifying information and - except for the expense, which is carried forward to his personal tax return as a loss - all zeros. Is it still necessary to file this return? He says he likes keeping the company alive, "just in case" a housing project should come along and I think he still likes signing the return as "president." I fill out all the paperwork every year and, of course, charge him for the effort, but is this really necessary? Thanks.