Because it forces one out of the tunnelvision which is stuttering. It could be how clowns are scary to some, but if you can get distracted from your feelings you will not know your opinion on dubious matter. This is why focussing on it, is mainly the first state. You will get the hang of it, and be able to multitask multiple viewpoints verbally, without the viewpoint of stuttering interrupting. It’s helped many, but not only stutterers. Human performance is generally impacted by their ability to focus, and many people get distracted which degrades their performance. To focus is a good thing for anyone. Focussing on an impossible task, is the same as lifting a heavy weight. When the time comes for a possible task, you will know without a doubt you can do it.