They have hired some spammers in the campaign (not everyone). They don't give priority to quality, they only need quantity.
Yes, there have been cases of many members of that campaign who were breaking the rules of the forum and doing things which this community doesn't accept. However, it's not possible for single person to look after all of those things and that's why spammers do their spamming activity without any fear.
They must hire someone for managing the campaign. Or at least to monitor the participants and replacing the spammer.
I believe a large campaign like Stake should have more than one manager or a manager with some assistants. There are some good members who are also part of that campaign but it's also a fact that some members of that campaign are taking advantage of the manger who's hiring them as participants.
It's a quite hard job to manage a campaign where most members have to make so many posts and for a single person it's not possible to go through all of the members and their posts to verify that are those posts legit or those are recycled ones or are AI generated ones.