I understand your point, and I agree that cooperation, friendliness, humility, etc. are all extremely important skills in any engineer or developer, but I think there is some value in looking at the two things distinctly (technical and social).

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.