This conversation has one foot in design, another in engineering and yet a third in marketing.
Simplicity is about the usage of the product. It effects the user. Complexity as present here, the 'amount' of features is about the purchaser. These may or may not be the same person, but they definitely have different perspectives and the criteria for purchase and usage are different.
These are very different contexts. The reason that users buy a particular product is for the benefits (pardon my marketing hat). In the early stages of diffusion people may buy based upon features, but that is primarily because they either do not know how to assess the benefits, or they are technically inclined. By the time a product finds its way to the mainstream of consumers the features have been translated into benefits, typically by information leaders (walter mossberg), and into brand/product specific recommendations.
If consumers buy complex (many features) but want to use simple, then there really is not any dissonance for the designer. The real trophy comes from designing feature laden products in a manner that lets them be operated or controlled simply (duh). Preliminary research will help to determine the thresholds of product feature inclusion, and the marketers will detail the multitude of feature benefits to list on the packaging.