I don't understand the connection between free speech and bombarding the forum with low-effort posts. A copy-pasted article is a low-effort post, especially one that doesn't include a personal opinion or additional analysis of any kind. Spam and low-effort posts are against the rules and should be deleted.

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".