If your really serious about developing stuff what will end up running on a Linux server, I think you should really be using Linux on the development machine. I know that is not always practical, but more people should do it. No one would dream of writing a Mac app on Windows, and I don't see why Linux should be any different.
If you're targeting a specific platform, it can make sense to use a virtual machine instead of installing that platform on your development machine. As far as code is concerned, it doesn't care that you're running it on a Linux VM inside a Windows dev machine rather than directly on a Linux dev machine.
That being said, if you're trying to target Mac or Windows, it's generally a good idea to use that specific platform's tools. It's reasonable to develop Windows and Mac apps on Linux but it may not be the best environment to do so. It's really up to you as a developer to determine the best toolchain and processes based on what you're trying to accomplish.
