> Because if they wanted them they would buy them?
Only if they can afford them and can justify the purchase. People want many things that for various reasons they don't acquire. It may be cost (units would have to be sold at a loss to get down to consumer-comfortable pricing), it may be that it's part of a larger system. For me to get a new AMD CPU I'd also need a compatible motherboard and, possibly, different RAM (either for physical compatibility or to get an actual performance improvement, even if my old RAM "works" if it's sufficiently slow it's a bottleneck that makes the purchase not worthwhile to me).
