I think that your argument is with the part about a company being worth $0 if it's not cashflow positive? In theory that's the case but obviously it depends on

I think that your argument is with the part about a company being worth $0 if it's not cashflow positive? In theory that's the case but obviously it depends on a lot of factors, and if we're talking about software startups then they typically would have very little in terms of assets to unwind. Maybe some office furniture or a bit of IP. But most of the cash is going to stuff like employee salaries, leasing office space, and cloud computing infrastructure, so by the time you decide to shut it down there's going to be very little left in terms of shareholder value.