As far as my experience says, nobody ever took a bug just because it was open. Those issues just annoy all of us for ages. From time to time, there is a business need (e.g. someone is willing to pay) to solve some of them, but that happens with issues resolved as won'tfix as well. It is easy to reopen them in such situation. There does not seem to be a value in keeping issues nobody plans to work on open.