I don't think it's a stupid question. I've also wondered if it might be possible. There are, however, some downsides.
1. Someone has to place the questions in the correct folder. Maybe the OP knows which folder, and maybe not.
2. Also, many times a poster asks for a certain type of solution, such as macro, formula, etc., only to end up with something completely different.
3. If the posts were placed in certain folders, I know I would presrceen them for topics I am interested in or feel I might be helpful with. I would miss seeing some very interesting post and miss the chance to learn new things