It's forbes. Be prepared for interstitial ads.

Here's the one reason:

Top talent leave an organization when they’re badly managed and the organization is confusing and uninspiring.

This goes along the lines of what Joyce was just saying: it's gotta be a good mission, and the people need to have the ability to work on that mission without other people getting in the way.

Why would top talent work for idiots or something they don't believe in?

A more interesting question is why they stay is weak companies-- I think Yahoo held on to people longer than most companies because the culture was so cohesive. Every employee survey said the number one reason they stayed was because they liked their coworkers.

I think employees also have inertia. If there's nothing compelling them to leave, they will stay.