Because the buyers are consumer hardware companies. This means a) there's an expectation that software works just like their hardware: they put it together once and then throw it onto the market. Updating or supporting it is not a particular consideration, unless they re-engineer something significantly to reduce costs. and b) the bean-counters and hardware engineers have more sway than the software engineers: lower cost, better battery life, features, etc on paper will win out over good software support over the life of the product.