"In the private sector, when you run out of customers..."
And of course these businesses generally wish to remain in business, so it is in their best interest to keep the customers around. How is that so much different from Government bureaucracies?
And I disagree with your blanket assessment of all Gov't programs that aim only for self-preservation. (OK, so maybe it wasn't a "blanket", excuse my hyperbole!) Certainly there are far too many of these, but at some point, if a Gov't is to be re-elected, it has to be fiscally responsible and get rid of unporductive programs or aspects of programs.
Maybe that is a shortcoming of the US two-term limit? In your second term, you can afford to throw caution (and cash) to the wind, you're not gettting back in anyway.