My experience has been different. If a person is in maniacal love with an idea (not not the business), then of course my entire post is irrelevant. It is only applicable if the person him/herself wants an honest introspection of whether what they are doing is right or not.
A founder puts in a lot of effort into an idea and the gets disappointed when entire world ignores that idea. Instead of getting generally frustrated or feeling disoriented, asking these simple questions can at least provide a direction to the founder.
If they've not asked these questions of themselves during the first few weeks, that's fine. If they've not asked themselves these questions in the first 3-6 months of work, there's problems.
Whether or not they've asked these questions can usually be found in some sort of action plan they're working. I don't care if it's 10 words on a whiteboard or a 10 page 'business plan' - it generally shows they've thought about market size, steps to reach the market, potential value, etc.
Someone external to them asking these questions might help reorient their thinking, but if someone's capable of going months long in to something without the capability of doing some of their own introspection, they've got bigger problems than just this particular startup/project.
We may have worked with different people (likely very true), but this has been my own experience. There's 5 startups I've talked to over the last year beyond just a cup of coffee style meetings - multiple meetings, talking financials, markets, plans, code, etc. Only 2 had real plans that they were executing - the other 3 kept digging in their heels insisting I didn't "get it" or similar reactions.
I like the "value it creates per customer" question. The problem with business plans is, people identify a target market of "everyone with an internet connection, times an arbitrary adoption rate" (1%? 0.1%?).
In reality, your target market is "everyone you can advertise to". That's probably 10k people through social media, and then $1 / customer (wild man guess) per google ads click. You then need more than 0.1% of the target market to sign up to break even.
if you really got 2 out of 5 startups that had some bearings on the idea and pro approach, then I would say you were very lucky!
as we are full sail into that era of dropouts become billionaires, I am getting tons of emails from people who start and ends their idea on "I know how to kill Facebook and everyone will love it".
I think the numbers were a bit high... but out of 5, two are actually making money, have repeatable processes, and have small profit at the end of each month. Whether these will turn in to large scale concerns, I can't say (in at least one case, probably not).
And on top of that, I'm discounting probably another 8-10 "startups" I'd talked to during the last couple of years that - at that stage - weren't much more than a guy hacking on code, or people with an idea. Not to disparage that - follow your dreams - that's fine - but... only one of those struck me as ever being able to get to a point where they could actually make sustainable money.
A founder puts in a lot of effort into an idea and the gets disappointed when entire world ignores that idea. Instead of getting generally frustrated or feeling disoriented, asking these simple questions can at least provide a direction to the founder.