It sucks, but there are lots of markets where the customer says "please lie to me" and gives their business to the person with the most reassuring lie.
How can you possibly sustain a long-term business when you're so willing to damage business relationships?
However, the startup that (wins a big contract with a big promise && delivers on its promise) certainly has a larger chance to become a long-term business than the ones that short circuit themselves out by not winning contracts.
I do think it's much more common in highly competitive markets with no barriers to entry. Google/Facebook/Apple have pretty strong moats and large diverse markets, and can afford to release products "when they're done" and not talk about them until then. People in very competitive, low-margin markets often need the sale now. But then, people in the latter type of markets quickly get filtered out of the marketplace regardless of what they do.
There's a lot of cases where you are certain you can build what the customer needs, but you can't spend resources on it until you have a sale in hand.