The difference is, Tesla is a car company and Alphabet isn't. Tesla is hoping autopilot can help them ship units, and Alphabet is hoping they can make the tech

The difference is, Tesla is a car company and Alphabet isn't. Tesla is hoping autopilot can help them ship units, and Alphabet is hoping they can make the tech first and either build a car around it, or, more likely, license it to people who know how to make cars. I'm not sure either is altruistic.