The reality that I've experienced is: Most any function in a software company can be learned to an effective degree by anyone, if you take the discipline seriously, have the right mentors, and dedicate time to do so. Engineers can learn to be good founders and salespeople. Marketers and managers can learn how to commit code.
The reason, I tend to think, why business-focused co-founders might be less valuable than tech-focused co-founders in a tech company is, in my experience, that all founders surface their own biases in how their companies are designed based on the comfortable experiences of their past; and you need those biases to lean toward the tech in tech companies, because tech can automate anything per the previous paragraph.
I've seen this surface subtly: "Yeah, Stripe integration to take money makes sense, but its just not a priority right now. Sales can handle invoicing." (it never becomes a priority because once you give DepartmentX that responsibility they'll fight to defend their turf).
I've also seen it surface less subtly: A VC-backed software startup with mid-eight figures of funding, all the investors thought the company was selling software, but it turns out the salespeople were never trained on that, and were instead told to only sell white-glove services, using the software, from another department. "Bigger contracts" etc. Engineering leadership was oblivious to this happening for at least two quarters, because who knows, users were still signing up, "sales handles the invoicing", they weren't tracking the right things, maybe some layer of intentional deception. Chicken & egg "the software doesn't sell" "you weren't even trying to sell it". Engineers are expensive -> Engineering layoffs. They're now a zombified services company, who took on 70 mil in venture capital to sell software, with zero full-time software engineers. The CEO's professional work history? Selling services of this exact kind for some provider for twenty years. They took rocket fuel to start a bonfire, and it blew up the block.
The reason, I tend to think, why business-focused co-founders might be less valuable than tech-focused co-founders in a tech company is, in my experience, that all founders surface their own biases in how their companies are designed based on the comfortable experiences of their past; and you need those biases to lean toward the tech in tech companies, because tech can automate anything per the previous paragraph.
I've seen this surface subtly: "Yeah, Stripe integration to take money makes sense, but its just not a priority right now. Sales can handle invoicing." (it never becomes a priority because once you give DepartmentX that responsibility they'll fight to defend their turf).
I've also seen it surface less subtly: A VC-backed software startup with mid-eight figures of funding, all the investors thought the company was selling software, but it turns out the salespeople were never trained on that, and were instead told to only sell white-glove services, using the software, from another department. "Bigger contracts" etc. Engineering leadership was oblivious to this happening for at least two quarters, because who knows, users were still signing up, "sales handles the invoicing", they weren't tracking the right things, maybe some layer of intentional deception. Chicken & egg "the software doesn't sell" "you weren't even trying to sell it". Engineers are expensive -> Engineering layoffs. They're now a zombified services company, who took on 70 mil in venture capital to sell software, with zero full-time software engineers. The CEO's professional work history? Selling services of this exact kind for some provider for twenty years. They took rocket fuel to start a bonfire, and it blew up the block.