Saving a fortune for ASA?? I suspect that the big end of town said that they don't need, don't want and won't pay for the NDBs around the country. Just goes to show that the user pays model for aviation
The interesting thing - if you study the list of back up aid locations - is that NDB's in remote & rural locations are the major navaids that are being left. It's the areas around the major cities that are going to be devoid of any ground based aids. VOR will become nearly worthless for GA. Pretty much only VOR's Sr. Primary airports will be left.
God help you if you want to do VOR or ADF training or currency in the Melbourne basin after the shutdown.
GPS is not infallible. It's subject to RAIM outages, jamming and equipment failure ( notably antennas). It would be nice to have some redundancy of AIDS for GA - not just the airlines.