I can't find the video, but in a Challenge of Champions pool tournament, the rule was that you had to call the nine. Efren forgot to call a hanger and lost a game. It's not supposed to be about that sort of thing and avoiding bullcrap like that is important to preserve the fairness and structure of the game.
Taking out call shot also removes the possibility of the opponent either misunderstanding your call or maliciously pretending not to have heard you call it or to not have seen you point the cue or whatever you did to call it. I've had people do both of those things to me. Strickland had an incident where he accidentally called the wrong ball, even though it was obvious which ball he was shooting. It's better to just avoid this whole problem all together.
As ridiculous as your example, and at the Challenge of Champions (approx 2004), Jeanette Lee (I can't remember who her opponent was) stood at double hill breaking. She broke wet, pocketing several balls including the nine ball. For good measure, she also hung the one ball a few inches from the side pocket. She won the set, or did she? They were playing the nine didn't count on the break. No matter, for the runout could not have been more simple. Unfortunately, the cue ball had ended up near the foot spot. There was barely enough room to spot the nine and once it was spotted, it was almost, but not quite, frozen to the one, and Jeanette was snookered. No good kick into the one ball was available, so Jeanette had to push, but finding a good push when the one is leaning over a pocket was not so simple, Her opponent ran out after the push. Ouch!
At the 2009 Challenge of Champions, Pan Xiaoting was on the double hill against Allison Fisher. The shot she looked at would pocket the three ball, and she also looked at a carom on the nine ball that looked like a good chance. She missed the three but made the carom nine. End of set, right? The crowd applauded loudly, having no idea that the nine hadn't been called, some not even realizing that it had to be called. It turned out the set was not over as they were playing that you had to call the nine. The nine ball was spotted and Allison approached the table, but the referee stepped in, explaining that although Pan's nine ball didn't count, she retained the inning as a ball had been pocketed. Allison dejectedly returned to the chair and Pan ran out to win the set.
In each case, the players had to endure truly ridiculous results and the fans were confused and mystified by the rules and how they were applied. Call shot just doesn't work for the casual fan.