Although I agree in general, there is a valid ulterior motive to playing the "stealth startup" game, and that is as a marketing strategy to generate buzz prior

Although I agree in general, there is a valid ulterior motive to playing the "stealth startup" game, and that is as a marketing strategy to generate buzz prior to launch and drive user adoption on launch day. IMO this is really no different from a "private beta" strategy or "sign up your email pre-launch" strategy. However, the only founders who can generate any real marketing traction on the "stealth startup" play are rockstars: "John Doe is working on a stealth startup" is nowhere in the same league as "Naveen Selvadurai is working on a stealth startup." And I would argue the sheer marketing value of the latter warrants the secrecy.