None of the insights they talk about are particularly noteworthy or trade secrets. They could have been discovered as part of coming up with their business plan. It's more than fair to assume they'll make the mistake again.
It's not strictly off-topic, but it's a nasty, generic dismissal. Piling onto other people's mistakes ("They could have been discovered as part of coming up with their business plan") is a lousy thing to do, and if you're going to do it here (though please don't), your comment should have at least have some other redeeming quality. Instead you draw contemptuous conclusions about someone's character, kicking them when they're down.
This is the sort of comment that, even assuming it's 100% correct, says more about the commenter than its subject. I'm ashamed to see things like this on HN and particularly ashamed that they routinely attract upvotes.
I am a single poster/person, not a group of people or a pattern of commenting.
The trade secret is in what's not mentioned: what's wrong with paper menus?
If a user insisted on written documentation for a project that moved quickly, how would you manage that? Would you give them a printed copy? Or would you say "the latest docs are at <uri>"?