The longer it takes to cool, the more chance bacteria have to get in there and go to work before the yeast. And, wort is heaven for bacteria...it's essentially an IDEAL growing media.

Now, why the ice method is bad is time. It takes hours to cool the wort, and hours is plenty of time for the bacteria to get started.

A wort chiller is the way to go. It can cool down your wort in 15 minutes. Pick one up and enjoy the instant improvement in your beer

For my own benefit, just so I understand a little better, can you clarify this point please... I assume you are saying that chilling the wort quickly improves the flavour for it's own reasons and you are not referring to the bad flavour caused by bacterial infections?