It strikes me as a mistake to apologise for something that you shouldn't apologise for.
I thought the video was humanising, and if anything, he remained cool in the face of threatening behaviour. Apologising just legitimses the critics, who'll remain critical regardless.
For me the video humanizes Uber drivers - the people who have the most to lose when Uber brass damage the company through scandal and mismanagement. The fact that Kalanick dismisses the driver's opinions on what might be good for the company reveals the fragility of his ego. If he'd listen to the opinions of the people who actual make Uber work, he might learn a lot.
I thought the video was humanising, and if anything, he remained cool in the face of threatening behaviour. Apologising just legitimses the critics, who'll remain critical regardless.