The thinking is this: If he really had the same question, the exact same question, then there is no point in asking it again, it's already been asked and answered, or answered as much as it's going to be. If the existing answer helps someone else then maybe a comment like 'Thanks for this, I had the same problem and this helped me fix it'. Clearly that wasn't the case so it's not the same question. The question might be related and it might be useful to have a link back to a related question for extra background in some cases, and that's fine.
Keeping to one topic one question keeps the forum tidy. The alternative is a question followed by hundreds of replies, with lots of other questions buried in there somewhere and a nightmare for anyone to wade through.