Rabbit trails go here, there, and everywhere, and pretty much tend to lead nowhere. (Have you ever watched a dog sniff out a rabbit trail? It wanders in small then wider circles, around and around, feverishly looking for the rabbit - literally, a meal and, figuratively, the point of one's argument.) No one knows what's at the end of a rabbit trail (the point of one's argument). Is there even an end to it? It's a confusing maze of pointless leads. In short, a rabbit trail leads (us) nowhere. It serves only to confuse the prey/the reader. It keeps them preoccupied and confused. ;-)