Having seen this debate pop up over so many of these discussion boards and then the fur starts flying, the two distinct sides are the business of radio (the money side, the advertising side of the industry, who are looking for ratings, which equal advertising for the various products that Madison Avenue wants to help sell, whether it's cars, hamburgers or funny blue pills for a certain part of the male anatomy), which seems to cater to the more casual listener who might have the radio playing in the background while working; the type of person that DavidEduardo or TheBigA would consider the typical radio listener, and then there are the people who like to listen to music for fun, as a hobby, like building scale model cars or observing the stars and planets through a telescope. People like Oldies76, Avid Listener and myself who want more variety in their radio stations' programming and who get tired of the same old songs. In reality, there is truth in both sides of the argument: after all, the radio stations are going to go "queep" and die without advertising (the like of commercial-free KCDX in Florence, Arizona notwithstanding; but even they have to appeal to the public for donations, even though the guy running the station himself has a lot of money; it might take ten thousand dollars a day or more to run it, which would be prohibitive even for a multi-millionaire), and the people who make cars, hamburgers, and so forth can't sell their products without advertising them (even though they don't advertise to me: the minute the commercials come on my car radio, I'm switching to another station that's not playing a commercial, guaranteed!), but at the same time, larger, less rigidly-controlled playlists would help the likes of the "hobbyist" listeners stay tuned to the stations longer. Whichever side ultimately wins out, it's obvious that we're not changing the other side's mind and gee, let's sit back and relax, enjoy a ball game or the swimming pool, or if, like me, you build models, "cutting some plastic."
By the way, I find it helps to like several different kinds of music; scan through my car radio and you'll find about five different music formats, from hard rock to oldies to country to old-school R&B.