Skill is probably one of the most important qualities to look at when hiring, but it is not the only quality. The person must have the right balance of potential, aggressiveness, acumen, collaboration, etc. Skill alone will not get you much in a large company.
Having said that, diversity is also important so that you do not become insular in the thinking that could mean missing the next leap in technology. Microsoft suffered from that and is just now starting to recuperate.
I think the only problem has been when someone is hired purely based on the diversity issue.
Get people that have passion, skill, and can push the company in new directions. That comes from many faces, some male, some female, and certainly from multiple races and ethnic backgrounds.