I think you're not understanding what their goal was/is. Not everything is a business. Not everything is paid for. As I recall, the last time wikipedia did a request for funding, they were very happy with the results. It's a charity asking for funding. Not everybody has to pay. Not everybody can pay, but even those who can't pay benefit for free.
"shut it down, and then startup a for-profit with the same information", is completely wrong, as the people who created the content did it for the purpose of providing it for free to the world as a resource. That is the value. They would likely loose the submissions and quality if they did this. Though it has been done before. Gracenote CDDB was open sourced, then they closed it and left the open source version unapdated which was the instigator for MusicBrainz to create an alternative.