I kind of see where you're coming from, Slack, and it's always been something I've tried to avoid... I'm not a fan of those pieces where the descriptive imagery goes overboard to the point of being incomprehensible, not to mention difficult to put a tune to.
I guess it's all down to what the writer wants - if they want to write something that's going to have the listener humming it all day and singing along on the radio, then that's going to turn out markedly different to a piece where the writer wants to raise the hairs on the back of the neck of the reader/listener by using beautiful language and images... by nature those two things are very different.
I'm certain that at least a good proportion of the biggest hits of the past 30+ years would be ripped a new one in this forum, simply because we are lyrically based, as opposed to musically based. As the only way we have of influencing the readers is by the worRAB we place on the screen, the only real way of impressing the readers is your lyrical content.
Of course, there are plenty of decent banRAB out there who write excellent lyrics and fit them to music extremely well. I guess it's all down to what your particular flavour is... there's a n00b running around at the moment (Tears Of Tragedy or something) and he's writing in an almost carbon copy of Fall Out Boy's style... that's not going to get him particularly high marks here, but as far as he's concerned, that's the music he enjoys, and that's the music he wants to write... therefore I guess that technically, he's not doing that bad a job, even though I chewed him out for it, as it wasn't something that appealed to me. It's all a big game of opinions, really.