In some cases it takes more than one move to exploit a weakness. There are some situations where, after you fill all the dames around a group, it is possible to kill some stones, or make a seki, or start a ko. When you play the dames, the opponent often becomes suspicious, thinks about it, and adds a move to defend, but not always. Sometimes they don’t see the threat, they lose some points, and they learn a lesson.
With the anti-stalling feature, the opponent wins without learning the lesson, and later when they play in Go Congress they lose a game because of it.