But there is another reason why admins might be looking the other way.
The forum culture is generally dying out. People don't want to write on online forums as much as they did before. The press board (spammy as it is) still generates traffic in the same way that the altcoin boards do. The admins might not be willing to put another nail in the coffin by deleting a massive amount of threads in the altcoin and press boards and start banning more people. After all, "all publicity is good publicity".
I doubt that this helps the forum. It gives backlinks and therefore possibly some search engine boost to those "news" sites but seems unlikely to work the other way. I tried googling some of the titles from the Press board and in many cases Bitcointalk is not in the results and sure as shit none of those sites will link to Bitcointalk.