I'm expecting C-ship to last for at least 10-15 years.
You have to understand that the C-ship allows the Feds to suck in every penny of profit from these companies, while the shareholder will see none of it. The C-ship allowed these companies to become a sort of a gigantic piggy bank for the feds to reach their dirty hands into when they find themselves needing some cash for whatever pork project that happens to be on the agenda.
From day one, it was the intention of the Feds to milk and bleed these companies dry, and thats exactly what they are doing as we speak. The Feds love the C-ship, and thats why it'll continue for quite a long time.