The only problem I have with avoiding answering questions that have been asked before rather than asking again is that my answer is not likely to be seen. This includes fluther and the merging of duplicates on other sites. I see lots of questions that I would like to answer but I know that, odds are, my answer is not going to be seen. I have seen lots of great questions here that I pass on because of that. I have to be, in my mind, writing an answer for only myself or really care about the subject to answer them… which I sometimes do.
I am annoyed by the frequently asked questions, such as the intermittent flood of 2012 questions… which is going to be very obnoxious next year. I also become extremely tired of such things as the Bush/boot incident, the flood of questions after Michael Jackson died, etc.
I understand why it is done and, actually, like how Fluther does it rather than merging because the question can be brought up more than once, even if it is not frequently. In sites where these are merged, often questions that are the same on the surface, but really are not the same, are merged and, thus, some of the answers are not answering the question. Also, when you have a kazillion answers to any question, merged or not, yours (the generic “you”) is not going to be seen.