[Solivagant]

Personally, I'd rather get repetitive responses than have my thread closed. There is always hope for more responses. Plus it is kind of like when you go to a doctor for something, you sometimes need to consult more than one doctor to be sure. So I think more than one response will just reassure them that yeah, this is what they need to do and all that. Moreover we're not professionals so having more than one opinion (even if they are all same) can be reassuring for the members. Personally, I know that I'd prefer to hear more than one person saying the same thing to be absolutely sure about something. We know that the response that everyone is giving us adequate but the OP doesn't know that and I think there's no harm in more people posting the same thing. It'll only do some good. Besides, the members should be satisfied.
And in the example that Lynds gave the person could probably freak out more and would need a little calming down by people and having their thread closed won't encourage them to make a new one even if there is a Moderator's post encouraging them to do so.