The problem with any SDK is simply the cost. Why should I as a corporation provide a free SDK to you?I have to hire someone to make and maintain it. And what do I get in return? Nothing. (and the 'gratitude' of the homebrew community isn't something they care about one iota, no matter how important you think you are). If you can't make money off it, why should you spend money on it?
And before you say XNA. XNA is basically a tool to get people into the DotNet ecosystem. There's also an annual cost.
And before you say XNA. XNA is basically a tool to get people into the DotNet ecosystem. There's also an annual cost.