AM radio is annoying because of the FCC. When the stations are forced to power down at sunset, you can’t get any reception.
Sorry, but the FCC did not create the ionosphere, and has no control over how radio signals propagate. They are trying to prevent chaos.
Actually, you may get too much reception
see http://followthatmouse.wordpress.com/tag/dx/ an interesting read on DX and AM radio, one of my hobbies as a youngster.
When stationed in rural NV (Lincoln Co.) I would set my clock radio to KSFO, (SanFran) the signal was that strong in the early morning. Late at nite I could catch the ‘classic radio’ episodes - Green Hornet, SHadow, etc.
Those were the days (Mid 70s)
As long as there are massive segments of the rural countryside seved by AM radio, it will survive.