This is one of the most annoying part of stack overflow,instead of closing the discussion,they should have a provision to move to more opinionated discussion list.
They do. When you vote to close a question (and anyone can do that, not just moderators), you have to give a reason. One of the predefined reasons is "belongs on SuperUser stack exchange," and another where you can fill in a reason, such as "belongs on Programmer stack exchange." (Programmer is for code review, style questions, opinion-based stuff, etc.)
My experience is that programmers.stackexchange is even more militant about closing questions than stackoverflow. I guess they got tired of receiving all of the unwanted garbage and it makes them extra sensitive.
