Originally posted by Peter Zack exactly. FF users would want more than could ever be packed in a camera this size.
Plus don't forget that theres more to a digital camera than a sensor. The body is packed with a small computer and thus is going to be larger. This camera (which was a peice of junk Btw - I had 2 of them that broke quickly) only needs enough room to fit a thin roll of film. So it would be tough to pack a FF sensor inside a body close to this size.
I, also, had 2 Minox cameras, first a 35GL, I believe, if I remember the model number correctly, which I used for several years and enjoyed very much. I also had the dedicated Minox flashes for each camera along with the nice real leather cases, and, oh yes, the Minox filters and lens hoods. They had a complete system. I sold the 35 GL to get the new 35GT which I used for probably 15 years. Neither of mine were pieces of junk, rather precision German miniature cameras with great optics that provided me with amazing pictures. Carried both cameras all over the world and never had a failure. They were awesome gadgets of the time and were a lot easier to carry than my bags full of slrs and lenses and assorted gizmos.
I agree that it would more than likely be a huge task to engineer a large sensor and the supporting electronics into a tiny package such as the Minox and also reach a price point where end users would purchase enough to make it worthwhile to the manufacturer.