I very frequently start new .NET apps, and I by no means "only ever code to pay the bills" (in fact, I don't work as a programmer at all anymore). Here's a list of a few interesting .NET projects: http://easyhook.codeplex.com/ http://ccimetadata.codeplex.com/ http://www.mono-project.com/Cecil http://daeken.com/renraku-future-os http://www.assembla.com/wiki/show/nethooker https://github.com/daeken/Dotpack (The latter three are mine, so I'm a bit biased there)

The .NET community may not have the number of hobbyist developers that Ruby, Python, et al have, but we do exist.