Can’t be bothered to watch the whole video at work so I apologize if this is in TFV.
If you can’t find one technically minded person who believes enough in your vision to drop everything and help you make it, that is not a good sign for your vision.
The video goes into why that's the wrong mindset. If you're looking for people who "believe in your vision", there's a good chance you're looking for an employee, not a cofounder. Strong candidates have their own vision, and strong teams build something out of everyone's vision.
It can still be the case that one person has an awesome idea that everybody else in the company signs off on. But chances are, everybody on the team is going to have to make some room for other people's ideas and takes on things.
That's why the willingness of a software developer to drop everything to work with you might not necessarily signal anything wrong with your vision.
If you can't find a single software developer who believes in your plan for better APIs or project management tools or consumer internet apps, it's a pretty good heuristic that your vision or ability to sell it sucks, or that you add less value than the dozen other people that talked to them about chatbots for X this week. Any prospective technical co-founder has a huge amount of insight into those markets. On the other hand, unwillingness of software developers to believe that the dullest sounding CRUD app going will be very exciting to grey suited men controlling a little known niche (probably precisely because hardly anyone's writing software for it) doesn't actually mean there isn't a market there.
Your product could be boring and useless except to a niche audience, but still a great business opportunity. In that case, people will only work on it for the money, and that is fine. Some ideas are simply harder to sell to potential employees:
“We’re making the world a better place through paxos algorithms for consensus protocols.”
“We’re making the world a better place though software defined data centers for cloud computing.”
“We’re making the world a better place through canonical data models to communicate between end points.”
“We’re making the world a better place through scalable, fault tolerant distributed databases with acid transactions.”
Yeah, I think the big difference is that devs might actually [be the only people to] think those sound like interesting problems to work on, whereas making the world a better place through [equivalent jargon in niche logistics/tax/pensions etc] only excites a small number of people who aren't devs, especially if it's not that much of a technical challenge and the hypothetical moat is just sales and business logic. Which leaves money, and unless the founder with the business model hires rather than looking for tech cofounders, it's really only a possibility of future money for working unpaid on something they don't understand on offer...
I don't think it's about the audience, but the company type. If someone is starting (random example) a food company based on their superior hot-sauce recipe and existing retail relationships, they probably don't need a technical co-founder. If someone is starting a company that "uses AI" to craft and target hot sauce recommendations, but doens't really know what that means and assumes they can get a shop to code them an app, that's going to be a problem. I think the latter case is what this is usually about. Many (most) business owners don't have technical co-founders and are fine, not so in tech.
In your first hot-sauce recipe example, that person IS the technical founder. Just technical in the field relevant to the business, which happens to not be tech.
The scenario in tech is more often comparable to some dude saying "I want to make a business selling the greatest hot sauce ever" and then having to go looking for someone who actually knows anything about hot sauce.
I think the idea that the person with the specialised knowledge of how to make hot sauce is the technical founder is an interesting point, but I think in YC/HN contexts it's usually considered to mean "engineer"; even in cases like accounting software where the founder who doesn't write software's specialised knowledge of the field is at least as critical as their partner's ability to convert that to code, the latter founder is the only "technical" one. Although tbh I don't think accountants or lawyers get offended by the insinuation they're the "non-technical founder".
If you can’t find one technically minded person who believes enough in your vision to drop everything and help you make it, that is not a good sign for your vision.