Well through the 70's, classical was a format that the FCC protected. I was involved as temporary GM of EZ Communication's FM in Richmond, VA, which was classical when they bought it in 1970 and was prevented from going to Beautiful Music by a vocal listener group that filed with the FCC. We had to arrange for a non-commercial station to commit to a certain number of weekly hours of classical and give them some money in order to make our change.The classical format was good for business in those days. There was a big community of audiophiles who listened to FM radio, bought FM Guide, and loved classical music. WGMS Washington DC was a great example. It was owned by RKO Radio. They were tempted many times to flip the AM to rock music, and didn't because of the public outcry. RKO was forced out of radio, but the new owners loved the money classical music attracted.
There were similar protests against classical music format changes, the most famous being in New York City but also being seen in markets like Chicago.
Few realize that the FCC supported the classical format by, essentially, requiring investigations of station transfers and even format changes if they dropped classical. Since licenses came up for renewal every 3 years, this was frightening to station licensees.
Because they were afraid of backlash back in the 70's and 80's.The station was extremely popular on Cap Hill. There was a well-heeled crowd that funded the National Symphony and Washington Opera. The Mars family (M&Ms), the Kiplingers (financial advice), and the founder of Geico were all huge supporters of the radio station and the classical music business. So they were able to keep the commercial classical format going for a while.
And they were still afraid of backlash if they moved even in "current times".Finally, they brokered a deal with WETA to move the format, the staff, and the rest of the property there, and the frequency became all news WTOP-FM.