I may have scuffed the problem with Mouw's Upside of Consumerism, but Anthony Sacramone hit the nail on the head.

update: Although it's on a different subject, R.R. Reno's reply to correspondents in the current Commentary fits quite nicely with Sacramone:

There is nothing in breadth alone that necessarily conveys richness of character or experience. On the contrary, I am more and more inclined to think that it leads either to confusion or to a sophisticated superficiality. Richness of character is like that of color: it comes form depth and intensity.