It could be another unintended consequence of digital technology as pop songs are constructed by digitally controlled machines and formulas that produce a level of perfection that doesn't capture the ear. I loved my old handmaid, British MG, but don't have an emotional response to today's much better sports cars.
Reinstating the military draft would probably improve the songwriting.
Hip-hop and rap kinda took the swagger out of pop.
All that said, I think Green Day produces good stuff -- ragged, tuneful, empowered, and not manufactured in a digital lab.
