Why are fallacies misleading?

Fallacies are arguments that contain some type of reasoning error. Regardless of whether they are used intentionally or by error, they weaken an argument by using erroneous beliefs, illogical arguments, or deception.

As a result, they shift the focus of a discussion to unrelated topics or side issues and can thus be misleading. For example, the genetic fallacy shifts the attention to the source or origin of an argument instead of presenting evidence to refute the argument itself.