My opinion - I would rather the threads be open for questions. I will admit that while I would love to end a challenge at the top of the leader board, my primary goal is to just finish the challenge and have a score to submit. I learn so much from the other players in these challenges. So, I am not playing to win the prize, therefore it doesn't matter to me if I give someone an idea on how to play. And, just because I see something that gives me an idea of someone else's strategy, I am probably still going to play it my way (which means my scores will generally always be on the lower end). I understand that others may be a little more competitive, but I like the idea of sharing the knowledge, or at least seeing the questions and answers posted as they come up.
And just to say it - I love the tournament, even if I don't participate as much as I would like.