And: Do conglomerates churn out torrents of garbage purely out of the evilness of their cold hearts, or are they merely rational economic actors who produce what the buying public demands?
This certainly raises the question of whether there are fewer and fewer great songwriters because there just isn't a big enough audience for great songs, and if there's no audience you can't make a living writing them. Based on my experience with young people who bother to listen to music at all, young boys and men these days generally listen to rap/hiphop stuff and they're primarily interested in whether the songs have a good beat or a thumping bass. Teenage girls and young women tend to gravitate more towards vacuous pop relationship songs.
Admittedly these are generalizations, but I don't think the generalization is unfair. Many in this thread have noted how there are a lot of great songs being written by Americana artists. How many young people today are listening to that stuff, much less blues or jazz? I'd guess the percentage is miniscule. I know that when I go to see those artists in concert anyone under 30 or even 40 usually sticks out like a sore thumb.
So I agree that the listening audience today is probably getting what they ask for and what they deserve.