I agree with bfv's comment from a engineering perspective, but PG's also made the comment that the reason the tech world's insanity works is because of the economics of it right now. The startups that go on to succeed tend to generate > 100x return on investment. So at the moment, it pays to keep churning out lots of companies with little attention to software quality or security. As long as 1/30 of them succeed, they can brush the failures under the rug.
But that was the whole problem back in '99: all these companies generated "value" without actually generating "profit." The economics "right then" was that people with no understanding of tech were swapping tech stocks with each other on the assumption that they would somehow magically generate money at some point in the future therefore they were valuable NOW. Imgur has like a quarter billion dollar valuation. Do you see Imgur returning a quarter billion dollars to anyone?
Oh believe me, I'm waiting for the day when it all collapses. And there's plenty of companies that fall into your description. But I'm saying that the 1 dropbox that makes a billion dollars pays for all the crap ideas that turn into bootstrap-covered-node-js-designed-docker-contained vaporware.