It's called the hook because you "hook" your audience into listening to you
They show that the batter doesn't overthink the situation, but the pitcher is being picky.
In the Batter's line he says that he just reacts in the moment. This shows that he does not spend a lot of time thinking about the situation. It also shows that he may not be smarter about the situation. It doesn't show the batter is not prepared or that he knows how important it is. The pitcher doesn't think the call to throw a slider is a good choice so he shakes it off. His exclamation that none of the pitches will work shows his frustration over the choices. He is being picky and can't seem to agree on the type of pitch to throw.
A cold, moonlit night on the beach.
Because it gives details of where, when something takes place.
