Seems to me that we came up with a solution for this problem a while ago: the Debian QA team. Right now it has eight people, and an overwhelming workload. I think a QA team is the right thing here; presumably it can have the discussions about whether particular packages are so stale they should be removed.
But I suspect that eight people is nowhere near enough people. Maybe I could join... Indeed, maybe the problem would go away if everyone who has posted a suggestion in this thread joined the QA team and started work. Maybe we need a way to make being on the QA team a sexy job, just like maintaining glibc or the kernel or X is.