The role of the anchor is very important and he has to make the conclusions in such a way that their channel will be benefitted. If he is not controlling the speakers he can't turn the discussion in the direction he wanted. So he talks more than the actual speakers and makes them forget the points which they want to talk and the entire discussion will go as planned by the moderator.
I do feel that shouting sometime is felt appropriate as the moderator has to control the participants or else the points would get misguided & diverted as well. This perhaps is the mechanisms to control the proceedings. This is ok so far everything remains under control.
" Be Good and Do Good "