Thanks Scotus. The thing is that shoes cause bunions, and bunionettes. In non-shoe-wearing populations bunions are almost completely unknown. Very, very rare.
If the base of the 5th metatarsal rides up on the edge of the midsole, that edge will actually traction the 5th away from the 4th, slowly tearing the cuboid-5th metatarsal ligaments and inter-metatarsal ligaments. Orthotics are casted non-weightbearing, usually, which results in the orthotic itself being too narrow for the foot. Consequently, the lateral edge or lip of the orthotic presents another foreign ridge upon which the 5th metatarsal base will ride. It's critical that the entire sole of the foot rests on a flat surface. Orthotics are rubbish - I've got a whole bag of them - and podiatrists hopelessly confused. This is a really good example, actually. The shoe doesn't fit the foot? Stretch it. The narrow shoe is distorting the foot? Put an orthotic under it.
How about just getting a shoe that actually fits the foot? The whole shoe industry is mad. A D width shoe is actually only wide enough for a B width foot! Really. And they've done that on purpose for a hundred years because narrow feet look seemly, sexy and civilized. I'm not kidding. Jam your feet in there if you want.