I'm a happy .NET developer, but sometimes I often feel that being so involved in .NET alienates me from a lot of useful tooling built for Linux. If I need a tool there's usually something out there for me, but I'm a mid-to-senior level ASP.NET developer that hasn't used Linux in anger since university, so I would probably struggle if I decided to move over to another language.

I doubt all .NET developers feel this way, but I'm willing to bet that a lot of existing .NET developers can't wait to fire up Linux and develop in a framework they love with full support.