mrclumsy,
In my experience, you get the occasional 100% fail rate. Rare as it may be. Typically, it runs from 50-80%, which isn't bad considering that in other industries it's consistently as high as 95% or greater.
Anyone can spend thousands of dollars on training for a CPL. That doesn't necessarily make one a good (or even employable) pilot. Throw enough money at it and anyone can get through.
It's the employers' job to sort the wheat from the chaff. Some people (regrettably) find themselves as the chaff.
That's life.