I think what he meant is that if you look into the process of how products and system are designed, you will likely find out most of them quite comprehensible,

I think what he meant is that if you look into the process of how products and system are designed, you will likely find out most of them quite comprehensible, and more than often made by a group of men/women that are not necessarily passionate about it. Hence with great passion and even average intelligence, there is no reason we can not achieve a far better product than the current one.