Without Visual Studio, which installs the C++ and .Net dev env, it's a pain to install anything which works out of the box in Windows.
Example: Perl or Python both have an installer but you have to update the system PATH, the console sucks so you can never use it, no simple way to keep it update unless you use the installer again and so on...
If all these goodies are available in a "unixy away" i'm sure Windows will be used by general Developers.