I have nothing against the notion that the founder need not be a coder. Telling business people they should code is like telling coders they should know business. Not everyone can do both.
There is a good reason, though, why you run into advice that you should have a techy co-founder at your side if you can’t code yourself.
I’ve seen a few startups that were in a very bad shape thanks to the wrong first tech hire. The first techy person you hire will normally have a lot of your trust, and her/his decisions will determine the future of your tech, including factors like being able to hire top talent later, and so on. I’ve been hired to salvage some software a while back. It’s not just about how bad of a shape the software was in, but the political battle against the first tech person that made the salvage almost impossible. I gave up after a week, and told them they need to get rid of that person before they can attempt salvage again. This is not at all uncommon, and can drag on for years, even after the org has grown to hundreds of people.
On the other hand, this is not necessarily brought about by lack of technical skill. I attribute it more towards a subconscious desire to fail. Some people simply feel like digging their own grave and hire an obviously wrong person for the job. For people that really want to succeed, things tend to work out.