Both your points are true. But for a startup to be successful, it needs to have customers, or at least users. The available market for a company is the dollar-weighted set of people who think that it's cool (or at least necessary). Young people caring a whole lot about climate change or racial justice speaks directly to what potential users are looking for, just like kids throwing sheep at each other and hitting the Like button spoke volumes about what startups would be hot in 2005.