The issue in my mind is that "all those smart and talented heads" which the article mentions, even if they're aware of the bubble, have no incentive to change directions.

Call me jaded, but I don't think most startups are created with the intention of improving society. So long as there's an Ouroboros effect of VCs funding brilliant engineers without truly revolutionary ideas, those engineers are going to create business models revolving around getting a big enough user base to justify high valuations, and eventual acquisition.

And businesses shouldn't be about exit strategies.