Part of becoming an entrepreneur - probably the most important part of becoming an entrepreneur - is realizing that the rules are just guidelines. People will give you all sorts of career advice - "never leave a job without another one lined up", "make sure you get a good raise every time you switch jobs", "don't call yourself a programmer" - but they're just telling you what worked for them, and in some cases it didn't even work for them. The guiding principle you should follow is "I'll deliver things of value to other people, and in return, I'll ask for things of value to myself."
My advice would rather be: Think.
"Think" is probably a pretty good way of summing it up.
Afterward, they either a) do another startup or b) join an established company, depending on how jaded they are from the experience.
I knew the full story of these startups, it was as told in the postmortem (one of which explicitly stated "we failed because of X"). Judging by some of the comments I read, some people don't want to believe the truth that's told to them. They assume they know more about the situation than the founder that lived it.
* It is usually hard to talk about failures and especially if one has contributed to the failure significantly.
* It gives a counter perspective to the rosy pictures painted about startups by the media and tries to right the balance of views presented to the aspiring entrepreneurs. It helps to provide a reality check of what can really be expected and if startup is really the reader's cup of tea.
* On a personal level, it is an attempt by the founder to lay it all out and move on. So obviously there is some melodrama in it. Considering that, there are so many people in tech who suffer from depression and never talk about it, and we really have to coax some to take help, now that someone really tries to share their turmoil with the broader community, we should rather be welcoming than critical.
After all, no one is going to fail their startup, just to write a melodramatic post on Medium. ;)
After that, I started another company.
Actually if they learnt something, they did not fail. Their startup just ceased to exist.
https://www.youtube.com/watch?v=NpXY6LBNUNk
;-)