The article doesn't say that a conspiracy within Wikipedia tried to bias articles. It says that a prominent industrialist and political contributor paid professional writers to alter Wikipedia articles to change the descriptions of his involvement in a political movement.
It's a situation where organized professionals are working against unorganized amateurs. If it takes conspiracies within Wikipedia to counteract that kind of influence then we perhaps need more of them.
Actually, the editor was rather amateurish. I have some doubt this was professional work by his firm that was paid for.
Fred