The reasons are chiefly economical: while PCs may have 10 times the power of consoles, too much energy are expended trying to use the PC’s vast resources, resulting in “an inferior product” trying to expend “a tenth of the resources on a platform that’s 10 times as powerful.” In other words, gameplay takes a backseat to technology. Not only does lead developing on a PC make a less interesting game, but the console versions are even weaker thanks to the limiting of gameplay for tech unavailable on the platforms.
One thing that bears out what Carmack is saying is that the biggest selling games on PC are games that require very little resources, like casual games, social networking games, and MMOs, which seldom require cutting edge machines.
The interview with Kotaku can be viewed here.
