Wikipedia:Simple talk/Archive 75 Flood flag
Also, even those that sit in those channels are not always watching them and things slip by. Less eyes is always more dangerous than more eyes. And your bot will not catch all vandalism as long as its not stupid vandalism like blanking or bad words. Secondly vandalism is not the only reason that edits should be visable. Sometimes there are changes that should be seen by the community to make sure there is concensus for them to happen.