Given that the search feature results in no results because search terms need to be fairly specific and we don't all use the same vocabulary, it's not really fair to blame people just because a question was asked last year and often replied to with (my favourite response by far): 'XX issue was discussed and settled'.
Generally I don't care about that myself and don't reply to necro threads either - dead longer than a month or so. But the general tone on these threads is pretty bad anyways over certain issues. I myself dislike the frequent Steam threads, the threads to nerf the game even though it's already easy mode, the threads to make everything easier of more automated.
But other threads such as how to use game features, how to see certain information, how to learn the mechanics of the game should each be responded to as though it were the first time being asked. To some people it can be a lot of information and an odd UI to learn and not many people will suffer through the out-of-game tutorial. A generous answer will encourage better game play and better habits here and in the game.