Finding a warm body isn't hard, but finding a competent moderator is. The current moderators spend an insane amount of time on their communities, and they are

Finding a warm body isn't hard, but finding a competent moderator is. The current moderators spend an insane amount of time on their communities, and they are very proud of the environment they have built up over the time. They are barely able to keep up with all the automation tools they currently have available. The new moderators would not have this dedication, would not have the tools, and would have to immediately deal with an absolute deluge of some of the worst content imaginable just because the community will view them as scabs. When all the dedicated people leave, only garbage remains. Who would want to be in charge of a pile of garbage?