He also addressed the decision not to make HD DVD a standard feature for the Xbox 360. “If you look historically at the attach rates (i.e. the number of DVDs purchased per DVD player) you will see that game consoles have a single-digit attach rate, while dedicated DVD players have an attach rate in the mid-20s,” said Collins. ”Microsoft knew if we put in an HD DVD drive that we would have to raise costs and disenfranchise our customers (that are primarily gamers) as the unit would become too expensive.”
To illustrate this he pointed out the sales gap between Nintendo's Wii, which debuted at a significantly lower price than either the Xbox 360 or PS3 (and has no next-gen media support) and subsequently outsold both by a considerable margin. Microsoft recently introduced a bare bones version of the Xbox 360, called the Arcade Bundle, to close the price gap with Nintendo.
Source: Home Media Magazine