Most forum moderation is just moving/hiding a thread from various viewing groups. So it's still there for mods/devs to see, but we, the general public cannot. Even if a forum has a 'delete' function, it actually just moves to a hidden forum until it's again deleted, or hits a time limit that auto-deletes them. =\

What may be an alternative is the option to vote on a new OP. Should someone's reply be inspiring enough to take the lead on the topic of the thread, this would be a better choice for new comers to the thread to understand what is being debated.