OK, this seems like programming 101, but the real value of sports pbp for a radio station in programming terms is as a cume magnet IF you can spread that listening out to other dayparts. If you are a music station, you have to work hard to try to convert the pbp audience to regular listeners when many of them may not particularly care for your music format. Often, focusing on personalities is a more productive route than focusing on the music to get them to stick around. Even with that, there was a real limit on the amount of Titans listening that KDF could convert to listening in other dayparts.
But sports pbp on a sports station is a much more productive programming element in terms of converting pbp listeners to regular listeners. You aren't fighting the music barrier and (duh) a listener who tunes in for pbp probably has more affinity for other sports programming than for a type of music they don't particularly care for. So it's easier to have a higher conversion rate.