Ask HN: Stealth mode seems like a weakness; why would anyone?

I've noticed some start ups call themselves "stealth mode" and get to >20 engineers and keep it that way. I see a lot of reasons why stealth mode is bad and good. Building in public: - tests your idea (+) - allows for feedback (+) - forces you to ship (+) - turns revenue into a usable metric (+) - opens you to copy-cats immediately (-) - opens you to incumbent challenges (-) - not doing well immediately can mean death (-) On the other hand, building in private: - keeps your idea secret (+) - launch with more feature-complete offering (+) - sort-of exclusivity for investors (+) - no customers = no pressure and vision focused (+/-) - no iteration/testing of vision (-) - admits that existential threats are real (-) I'm sure there are a lot more.. What are your thoughts?