I think the idea of technical and non-technical cofounders applies less to yogurt or restaurants than it does to most of the web startups discussed here. People can be passionate social networking, offering web analytics, and sharing photos without knowing anything about programming or having the skills needed to build these businesses.
I don't think many people decide to start selling yogurt because of a business opportunity. People that start yogurt companies are (hopefully) passionate about yogurt, and I would think they would have some experience in making their own yogurt. Starting a restaurant would be similar.
In summary, I think the main distinction is that the barrier of entry to programming (and engineering in general) is greater than that of making yogurt or cooking. There are many people passionate about computers and their applications that don't know anything about programming, but I would think there are far less people passionate about yogurt (and unhappy with the current offerings) that don't know anything about making yogurt.
Perhaps the analog/digital distinction is relevant here. If you are making yogurt, and you slightly deviate from the ideal recipe (leave the culture growing for too long?), you will probably get yogurt that tastes a little off. If you are writing code, and you deviate slightly from the ideal program, you will probably get junk: compiler errors, massive performance hits, blatantly wrong GUIs....
I don't think many people decide to start selling yogurt because of a business opportunity. People that start yogurt companies are (hopefully) passionate about yogurt, and I would think they would have some experience in making their own yogurt. Starting a restaurant would be similar.
In summary, I think the main distinction is that the barrier of entry to programming (and engineering in general) is greater than that of making yogurt or cooking. There are many people passionate about computers and their applications that don't know anything about programming, but I would think there are far less people passionate about yogurt (and unhappy with the current offerings) that don't know anything about making yogurt.