SuperUser has a much higher ratio of "personal" question. I mean that many questions are linked to one user only, with his particular configuration. Of course his question can be of help to other people, when it got an answer, and given that the user was providing the correct feedback.
However, there are plenty of questions which are rather abandoned, because the user only asked them and left them there, without adding more details or anything. A good example of this is when a question is migrated from SO or SF, to SU, and the author just left it like this, didn't create another account or associated it. Typically, we know that this one will never evolve, and with lacking details will never be "answered".
- Example of a question for which the author didn't come back since nor commented the answer: http://superuser.com/questions/71146/how-to-share-dial-up-internet-via-bluetooth
- Other example, a migrated question never claimed back on SU: http://superuser.com/questions/72458/copied-files-using-cygwin-isnt-found-using-samba
Since these questions are not answered, they will occasionally pop to the front page, adding noise.
When it's obvious that the original poster will never update his question (never took ownership back, or simply never visited since then), can we consider that he will never be interested in the answer, or maybe found it somewhere else? And in this case, should we close them as "no longer relevant"?
Note: I talk mostly about closing the ones which pop on front page, because going for a hunt on all old questions would be taking quite some time ;-)