People’s bullshit detectors have gone off on the launch of basically every single billion dollar tech company. That’s the downside of being early. No one believes it will work. If everyone believed it, you’re late. I’m sure I could find a comment such this, basically verbatim, on the launch post of every successful startup to come out of YC.
Startups fail by default. It doesn't make the pessimists correct. What I have noticed though it that successful startups are rarely, if ever, run by pessimists.