Remember, this business exists because of the musicians. Record labels need new music to put out and they're always looking for something good. One of the biggest worries I hear from bands and musicians is that the style of music they play isn't something that is popular or on the radio right now. I interviewed hundreds of people for the article and the only time current trends were mentioned was when it was something NOT to do. Production styles come and go.
Popular images come and go.
When I talk about a good song, I'm not talking about a good recording. I'm talking about a compelling piece of chords and melody that can be played in any number of styles. They are what make people initially react to an artists' work. While having sales can be helpful to gauge reaction to a band, it can be misleading. A good image can be very helpful to getting a band exposure, but if they don't have the songs, people will lose interest very quickly.