My argument is that startups are (or, at least, should be) inherently evolutionary. By that I mean you keep evolving the startup until you find product-market fit. The only reason not to keep evolving is when something pulls you away. Usually -- though not always -- the thing that pulls you away is, for lack of a better word, "life." In my case, "life" was my daughter's illness. For other people, it's other things. The outcome is still the same: failure.
Yes, we could quibble about specific reasons for why startups struggle, but, theoretically, every struggle can be overcome with enough effort/work/time from the entrepreneur.
Is the entrepreneur willing or able to put in that time? That depends on what else happens in their lives, which brings me to the core point of the article. It takes lots of time to keep iterating through the challenges startups face. Because it takes so much time, the unpredictability of life kicks in and often prevents founders from continuing to iterate.
Admittedly, my argument benefits from being a broad, macro view on why startups fail. In other words, yes, we can lump anything into a "life happens" category. But that doesn't make it false.