Nothing about making computers says you have to make phones (Apple). As the GP mentioned, nothing about search says you have to sell advertising (Google). And

Nothing about making computers says you have to make phones (Apple). As the GP mentioned, nothing about search says you have to sell advertising (Google). And none of the above say you have to make a self driving car (as both are reported to be attempting). I think you're drawing some arbitrary distinctions here. Making big bets in several areas is no small part of why Apple, Google and Tesla are magnets for the best engineers and programmers. There's nothing unfocused about marrying great software and hardware, which is ultimately what Tesla is doing. A lot of Musk's bet in AV is founded on the understanding that the existing automakers are/were quite capable of making a good electric car - they just have too much incentive to drag their feet. Autonomous driving will actually be the major differentiator in an industry that didn't have the software expertise to create a decent infotainment system.