To bring this thread sort of back on topic:
I think AM radio itself is more or less fine as is for now. This late in the game, there isn't much that can be done to bring listeners back. They've gone to FM and/or Internet streams, and they're probably not coming back. Just let it ride more or less as is to appease what little audience is left.
Do I like this? No, of course not. I really enjoy AM, despite its limitations (or perhaps because of them; I used to enjoy TV DXing when I was growing up in the late 90s/early 2000s, but once it went all digital, it lost virtually all of it's appeal). But it's realistic and pragmatic. The commercial broadcasters will go where the bulk of their audience is, and for better or worse, that's not AM.
c