If someone's social behavior jeopardizes the success of projects they work on, then perhaps it doesn't matter how technically competent they are.
If someone's social behavior jeopardizes the success of projects they work on, then perhaps it doesn't matter how technically competent they are.
As a counterexample to yours, what if someone is very friendly, witty, and amicable, but is severely lacking in technical skills? Perhas they are not even remotely pulling their weight in projects, resulting in friendly coworkers essentially doing their work for them and covering for them? In such a case you'll want to know that their technical skills are below what they should be.
It's very possible to have a bad stack ranking but excellent peer feedback.
With this system, someone who delivers very well, but undermines other people or projects they work on would likely receive a high stack ranking, but poor peer feedback resulting in private discussions. People in charge of managing said employee may ignore the problem, attempt to place the employee under people who will help them address social problems, or quietly find a way to move them to a different org. It's quite likely none of this shows up in stack ranking.