It stems from the state of people's brains at the club. Imagine how fast a mother reacts to her child being in danger. That's the reaction time you need across the team. If you instruct the players how to react in different situations, then they have to process that somewhere inside their brain before they do it, which slows them down. It's not going to be noticeable for a single player, but when you run it forward over all eleven players, their collective movements become a disjointed mess. The scums problem is that they're attributing this mess to tactics and transfers.
The best managers will give a few specific instructions, then trust the players to make the right movements for everything else. If you care about your teammate, and moving to the left hurts them, moving to the right helps them, that emotional feedback will quickly ensure it all falls into place and you move to the right instantly next time around. Because the scum players don't get that feedback, because they have no real feeling towards each other, they get their feedback from a video debriefing session the following day.