Peanut butter and hedgehogs: Yahoo!'s troubles
This part in particular really sticks with me. Pun intended. Passion is lost when you spread anything too thin. Brad spends some time talking about a business strategy which tries to do everything and does nothing exceptionally well—resulting in frustrated, unproductive and less than engaged employees:
Recommend reading the whole of David's post.
If you've not read it, in essence, Collins identified the key characteristics of companies that had consistently outperformed the rest of their peers. The Hedgehog Concept is all about having the insight to understand what your company can be best in the world at, what your basic "economic engine is" and having the discipline to keep focussed relentlessly on that.
Again and again Collins saw the best performing companies discovering and exploiting their own hedgehog principles, while their competitors seemed unaware of theirs and were easily distracted.