With the possible exception of the Lexington FM, these are all throwaway signals in small or medium markets. Other than religious broadcasters that air fringe programming only capable of attracting small audiences, I don't know who would be interested in any of these signals.
Evidently, the programming airing on these stations wasn't generating enough revenue to cover expenses.
Or it may have been doing just enough for the stations to barely make expenses, but the Cumulus execs saw the national trends affecting radio (AM in particular, but increasingly radio as a whole) and advertising, Unencumbered by any radio geekish nostalgia for AM, and probably making plans for retirement or employment in some other area of the communications business when the whole thing goes south, the execs correctly concluded that continuing to operate these stations was just throwing good money after bad -- and it doesn't matter what format was on them.
All valid points (though KZAC-ex-KSFO was in one of the largest markets, but I quibble); I see a couple of other considerations. One is focus. Yes, these stations were mostly highly automated, but there's still some overhead required to run them. That overhead isn't entirely financial in nature; it's also staff time and attention that should be better spent on stations (brands) in each local portfolio with a better likelihood of success. Shutting down the weak stations reduces the drain on attention and focus. It may not be a significant drain, but it's still a drain and one not outweighed by low revenue potential. The remaining financial burden is tower rent plus regulatory fees. It would be interesting to learn if Cumulus is giving up tower leases on some of these stations, but we won't find that out until STAs are filed for specific circumstances.
Then there's the matter of selling these stations. Anything can be sold if the price is low enough. But that then depresses the values and prices for similar assets in the future. These are highly illiquid assets. Thus, a fire-sale price will show up on comps the next time any owner, including Cumulus, wishes to sell or simply to appraise the value of the assets that it has. I believe that just relinquishing a license won't show up on appraisals, because what would have been a comp has then simply disappeared. Given what appears to be the precarious nature of Cumulus' capital structure, it probably wants to avoid devaluing its assets even further than they've already been. I may be giving Cumulus too much of a benevolent view here, but it may also want to avoid further depressing the general market for station sales.
This came to mind after I learned of a small chain in the Midwest that really, really wants to sell. When I heard the price, my reaction was that they would be lucky to get 25% of what they want, particularly given the economic conditions in their rural areas. The gap between buyer expectations and seller expectations right now seems to be huge. Sellers don't want to devalue their assets; buyers don't want to pay prices that they're unlikely to recoup. So things are frozen up.
In the case of one of the affected Cumulus properties, KLIK, its primary value in recent years has been its tower, in a location perfect for supporting cellphone traffic coming from vehicles traveling to and from the Lake of the Ozarks and St. Louis. Once Cumulus sold off its towers for quick cash, KLIK lost all value for Cumulus. I'm amazed it hung on this long.