Productivity Lost
Scoble writes about his first .NET application, written using Notepad. Of course, Don Box led the way by demonstrating .NET and XML based extensibility by using a DOS Window and Emacs. Some of us prefer productivity. When a marketing guy talks about development, and uses Notepad instead of your primary development tools, that doesn't say much in their favor. Doesn't even matter whether VS is good, bad, or indifferent - it's a perception thing. Have influential people visibly not using your development tools, and it makes people wonder.
