Comment by quickthrower2

Skimming the article I think he got caught by one of the killer issues that is worth discovering early: "Are you relying on other people's data, and can you continue to rely on it".

Scraping based ideas hit this issue. Ideas that attach to a single platform API too: X (formerly Twitter) killed many startups who relied on it's API.

This probably generalizes to "What are your dependencies, how risky are they?"

Which then covers people who rely on SEO rankings, or a single Instagram account for their entire business.