Obsolete Officials on the Field?

[fredhjr]

Have been watching the Cal vs Auburn game on TV. The announcers (and this is not the first game for this) question umpires' calls, even to the point of saying they are wrong. Why do we have officials on the field? Why not just let the announcers make all the rulings. Specifically, on a play at the plate, the PU ruled that the catcher juggled a ball while attempting to tag a sliding runner. The announcers disagree, saying "the catcher regained control of the ball". That's what I saw, too. I also saw that the tag was made with the glove, with the ball in control of the bare hand.