Unfortunately, small-town radio apparently could no longer make enough money to remain profitable by programming that way, and that is why many of these stations no longer exist.
Two problems with such stations: (both of these coming from personal experience)
1) They treat their announcers like crap, so you always have high turnover, and 19-year-old announcers who actually still think that they have a future in broadcasting.
2) They couldn't
take requests because they owed money to ASCAP, thus couldn't play anything published, or even co-published, by ASCAP.
Not saying that either of these were true of WTRB; I wouldn't know, since I never worked there.
The switch to "modern country" may have been out of necessity. The "classic country" was probably all on reel-to-reel tapes, LPs, or 45s, and would have needed someone to "dump it all" into the computer in order to continue playing it. And with an aging audience, that might not have been feasible.