I've been reading this recently http://www.amazon.com/gp/product/0954575016/002-8695533-6300821?v=glance&n=283155

Jerry Leiber (the wordsmith of the two) is quoted in there as saying the biggest difference between songwriting these days and his days is that now image is so important (in effect the urge to corporatise or brand 'popular' music talent by visual media) that decent or meaningful lyrics are no longer required to make a hit so why bother - the listener won't thank you for it by increased sales. You're selling a brand, a lifestyle and no longer a 3 minute lesson in life.

Obvious really I suppose, but I hadn't thought about it deeply enough until I read that. And I should have.