"Do not try to do everything. Do one thing well." Steve Jobs
The UNIX Philosophy precept #2: Make each program do one thing well.
Search the Internet for the phrase "do one thing well," and the results will include many examples of entrepreneurs and research scientists and others who have taken that small piece of advice to heart and demonstrated its power. Add to that recent research that demonstrates very convincingly that multitasking just isn't possible, perhaps even for organizations.