A better title might be "simplicity is used as an excuse for creating worthless software."
But anyway, Spolksy basically advocates finding the "elegant" solution, which is the one that incorporates useful features in an easy-to-use way. Hardly a controversial position. However his use of the word "simple" consistently conflates feature-poorness (lack of features) with ease-of-use. So when he says focusing on simplicity results in worthless software (as indicated by actual sales), he appears to attack ease-of-use. He's not. He's only attack feature-poorness. Cue confusion and controversy.
But anyway, Spolksy basically advocates finding the "elegant" solution, which is the one that incorporates useful features in an easy-to-use way. Hardly a controversial position. However his use of the word "simple" consistently conflates feature-poorness (lack of features) with ease-of-use. So when he says focusing on simplicity results in worthless software (as indicated by actual sales), he appears to attack ease-of-use. He's not. He's only attack feature-poorness. Cue confusion and controversy.