Depends. The spammers need to be banned.
We allow the competition to send their paid shills here so we can practice destroying them. But when they start posting the same previously debunked lies in multiple forums, then they aren't just shills any more, they're spammers. And at that point, we are no longer teaching each how to disarm these arguments. Instead, we're being held hostage by litterbugs. If we go out into the wider world, lies pile up in our own front yard.
I see no reason why we should put up with that.
That's why free speech has never been frowned upon here, but 'low value' (repetitive) posts have led to a great many being banned. And I say we evolved to do it that way for good reasons. That ain't broke. Don't fix it.