In addition to providing a comic interlude, what seems to be the point of the scene with the cab driver, Horwitz? How do Holden and Horwitz differ, both in their conversation and as characters

Horwitz is like Holden but worse. Horowitz has a really bad temper and gets annoyed over little things. This is what Holden is like but isn't as easily tempered as Horowitz. Horowitz seems like he has no friends like Holden and are both lonely at times. They even talk alike Horowitz tries to make a point across about Ducks but Holden keeps asking. Horowitz gets so angry like Holden does with Ackley and Straddler.