IMHO, Stack Overflow is not a debugging serviceStack Overflow is not a debugging service.
If debugging questions are now fine on SO, many people would just post such a question here, because they "have other things to do" than to debug their stupid thing. (In fact, I hate it debugging my own code for several hours and find just one missing line at the end - why shouldn't I post it as question on SO?)
Such questions would attract help vampires and drain useful resources from other programmers.
Some people may argue that you can "just ignore the question", but that is not true.
We have limits on the topic for a reason. We are not yahoo answers.
Limits on the topic are necessary, and the community has already decided that they don't want "debug my code" questions. (and similar: "convert my code from perl to C#", "give me the code please" etc. We had a reason for that, "lack of minimal of understanding", but that is gone now)
So I propose a new off-topic reason that includes "RTFM, debug your code yourself, and learn to read stack traces" etc. The actual reason should read nicer.