Question

Why does an author use active voice?

Answer 1

An author uses active voice to make his writing clearer and easier to read.  Active voice makes for a simpler work.  You are in the moment...you are current...you are participating in the current stream of events.

Answer 2

Active voice puts the reader in the action. The reader can imagine things happening right now, in the moment. Active voice also gives the sentence a clear actor (you know exactly who/what is doing something), so there is no ambiguity.

An author uses active voice to make his/her writing stronger and more authoritative. Passive voice can make prose more lyrical, but also more confusing.