That first question getting close votes is particularly annoying, because if the asker had not said that they weren't working on a game, I don't think it would have attracted any close votes at all.
I think that, with the recent drop in question quality (not that those questions are amazing), we shouldn't be tossing out perfectly good questions about DirectX / XNA / MonoGame / Unity / HLSL / OpenGL / etc, just because the person asking them isn't making a game.
If anything, I think we should be welcoming such questions with open arms.
Right now when people go to close such questions, they see:
This question does not appear to be about game development within the scope defined in the help center.
Programming questions that aren't specific to game development are off-topic here, but can be asked on Stack Overflow. A good rule of thumb is to ask yourself "would a professional game developer give me a better/different/more specific answer to this question than other programmers?"
I love the rule-of-thumb, I think it's very appropriate. I wouldn't want to change it because it says almost exactly what needs to be said. Maybe it could be bolded or italicised for emphasis?
Maybe "specific to game development" in the first line could be changed to "related to game development"? Not sure it's a big enough change, but it's a start.