Possibly because he knows JS+CSS, but not C, C++ or C#. Or possibly because the API's microsoft proposes are pretty horrible; I've worked on FF and chrome exte

Possibly because he knows JS+CSS, but not C, C++ or C#. Or possibly because the API's microsoft proposes are pretty horrible; I've worked on FF and chrome extensions, and I investigated IE support - but IE's extension model is truly terrible. Just take a look at that stackoverflow link you posted. What a mess. I wouldn't mind a clean C++ or .NET api, but the current API certainly isn't that.