But on the macro scale there are always windows of opening and closing opportunity on what makes for a viable business before (new technology takes over/bigger companies start paying attention/governments try to regulate you out of existence), and it is that more general climate of whether it's possible to execute at all that pressures the potential unicorns into a do-or-die mode. Monopolistic competition like e.g. Uber vs. Lyft is an exceptional case for technology; the expectation is that if you succeed at all you will probably be in complete control until the technology ecosystem itself shifts.

There is a second half to this, of course, which is that the type of people who found a fast-moving VC-backed startup are so deeply enmeshed in their plans for the company that they will put themselves into an unsustainable overdrive and expect everyone around them to do the same. Their enthusiasm can be entirely real and still be basically toxic and lacking in conservative sensibility. There are a lot of commonalities among founder personalities, IME.

Try reading it through the eyes of an investor putting capital to work rather than the person doing the work.