As a former Admin and Moderator of Anandtech Forums and member there since 1998 I have a unique perspective on the moderation and staff. The corruption you speak of almost certainly comes from the top and by that I mean Perknose aka Dave Perkins. He runs that forum like he is the Omnipotent Overlord and does not take kindly to any criticism. He also has personal vendettas against those who might disagree with him or even worse, criticize him. When he was first made Head Administrator of the forums another member, Bamacre, was also appointed as a Co-Head Administrator. This was done to keep Perknose in line but after a year or so Perknose with the help of a handful of his closest confidants on the staff were able to oust Bamacre from that position and have another close confidant of Perknose, Esquared, appointed in his place. With that done Perknose and Esquared went on a purge banning all the former staff members who were openly critical of him including myself and Bamacre along with many members who felt the same about him. He also purged some other senior staff members who critical of him though they weren't banned. He now runs those forums as if they were his own personal fiefdom and has made sure there is nobody in any position of authority to question him.
As for the Senior Staff, it is made up of long time members who before being made Admins spent most of their time in the Social Forums. It isn't a very tech savvy group and the average age is a lot older than the average age of the general membership. The best analogy I can think of is that they are like Politburo of the old Soviet Union, made up of long time members who are so entrenched that unless they get on the bad side or Perknose there is almost no chance they will be replaced by younger more tech savvy members.
Regarding them being volunteers, that much is true though the senior staff does get a stipend in the way of some used computer parts that Anand and his Technical Staff have reviewed and posted articles about. Nothing of a lot of value but still coveted by the Senior Staff none the less. After they are done picking through the best of it they then hand out the rest to their favorites among the Moderators.