Knowledge@Wharton has this great article with a conversation with one of the authors of Conquering Complexity in Your Business.  Some excerpts:

Complexity is a systemic effect that accumulates over time. So while you may have a perfect portfolio today, your customers' tastes are changing—what's good today is probably not good tomorrow. Many businesses respond by expanding their portfolio and placing more goods or services on the market. Each innovation may represent a source of customer value and profits at the time that it is introduced, but unless you have some mechanism for rebalancing that portfolio, complexity will creep into your processes, tax internal systems, and drive up costs. Even worse, you might strangle growth in the name of pursuing customer value.

Also, it consumes resources and can impede growth. If you have a portfolio of 4,000 products, you're spreading your marketing resources across all those products, when you should be concentrating on core brands. We also find in our work that companies with a complex product or service line have a significant gap in their understanding of what truly drives their profitability. What's important is that companies understand the relationships between complexity, cost, efficiency and growth, which we captured in a concept called the Complexity Equation. Management can then make rational decisions with these relationships being explicit, instead of implicit or unknown.  

As a general practitioner, this article hits a bit close to home.