One reason may be the company culture can't do both things at the same time? There's a world of difference between the kind of people and processes you want in

One reason may be the company culture can't do both things at the same time? There's a world of difference between the kind of people and processes you want in a safety-critical project versus a fast-moving app startup. Uber has to straddle both sides with great risk of leaning toward the wrong side in any particular scenario.