Charlotte Church did have a decent voice when she was younger, but by her 4th album she had taken on repertoire that was far too advanced for her voice at the time. From than on, she began singing things that were too difficult and pretty much ruined a voice that had potential with bad technique/training. As a singer with classical training, I can speak with some authority on this. I didn't know till I came across this thread what level she'd sunk to though. It's a shame.
As far as where all the good girls have gone, there are still a few of us left out there, but we're usually asking where all the good guys have gone.