If they don't care to, then that's their choice and why should anyone care? And if you do care, why don't you do the effort?
Implementing full Visual Studio integration is a LOT of work, so I wouldn't be able to do it on my own If Microsoft could reach out the Boo community and offer direct assistance perhaps that would help things?
Boo adds great value to the .NET platform. It would be awesome to see Microsoft endorse it!