You take down one, three more pop up. It's the same deal with the example you gave, torrent sites. And it's why a certain large torrent site is still around. To keep using the torrent websites example, they are simply databases which take maybe a few gigabytes of data? They're simple to keep backed up for everyone to download and re-host. It's a similar deal with exploit hosts, only much easier as instead of gigabyes they can be as small as kilobytes.
So to answer it in another way, there would be no point for Sony to target exploit hosts. They put their focus into stopping the exploits from happening in the first place. Once the exploit has been discovered, there's no stopping it from being used without patching it through firmware updates.