There are a lot of business and tech guys and most of all of them are pretty clueless when you randomly meet them in "gatherings".
But a valuable business co-founder brings extensive domain expertise, a network of people, sales skills, management skills, and fund-raising talent.
There's little point in arguing who is "more" valuable -- the business side or the tech side. They're both critical to have.
For some reason, this post equates the "business side" to the person with the "idea". But that's a strawman. Having an idea doesn't make you a "business" co-founder. Being a business cofounder means having a experience and talent on the business side of things. And a good business co-founder generally doesn't have a lot of trouble finding good tech people, because that's one of those business skills that they're good at...