While I took issue with a great deal of what Mr. Buffett said in the last post, there is one point on which I completely agree. Keep it simple! In my valuation classes, I begin my class by promoting the principle of parsimony. In the physical sciences, this principle (also known as Occam's razor) specifies that when trying to explain any phenomenon, you start with the simplest possible explanation before moving on to more complicated theories.
In valuation, the principle of parsimony calls on us to use the simplest possible model to value any asset. However, there is a catch. The definiton of simplest will vary, depending upon the asset you are valuing. When valuing cash, for instance, you can just count the cash on hand; you don't need a model or elaborate assumption. When valuing a mature company, with stable and predictable, profits, knowing what the firm generated in cash flows last year may be sufficient to value the firm. When valuing a young, growth company, the simplest model may require you to forecast earnings and cash flows for an extended period. You may not like to do it (I don't think anyone does) but there is no real choice..
So, here is the bottom line. I oppose detail for the sake of detail and complexity designed to show the world how smart and sophisticated an analyst is. I think you risk mangling the valuations of simple assets by doing so. However, I think to argue that detail is always bad and that forecasting is dangerous works only if you decide that your investment space is going to be populated only by mature companies. If you, as an investor, are interested in buying growth companies (and there is no law that says you have to be) or valuing them, you have to face up to the truth. There is no way to value these companies without peeking into the future and making forecasts, and then adjusting your value for the uncertainty you feel about these forecasts.