Why so little in body image stabilization?

Paul C wrote:

Nobody owns an interchangeable lens camera with no lenses.

Some people own an interchangeable lens camera and 1 lens.

Some people own an interchangeable lens camera and many lenses.

If I were manufacturing stabilisation, and it cost (say) £30 per item to implement, and I could make £5 profit per item on this area, I'd be putting the stabilisation in the lens. Of course, the converse is true from the consumer's point of view - so in body stabilisation makes sense for the buyer, but not necessarily the manufacturer.