Earlier quoted context omitted.
You need something more quantifiable than that when you're running a giant organization... Your approach would absolutely work in a startup of 20 people or less, but try that in the 10,000+ man Operating Systems Division at Microsoft and you'll run into some crazy logistics problems.
hiring/firing/raises can be done in small groups by their managers. What's crazy about that?
Every group gets the same number of raises, regardless of their performance, or effective developers in poor groups get nothing.
Stack ranking sounds like a shitty system, without a doubt. But I don't think you can have a well grounded opinion until you think about the issues it's trying to address.