Piracy implies theft and sounds more serious; where as copyright infringement does not sounds as exciting...

(from wikipedia...)

Copyright infringement is the use of works protected by copyright law without permission for a usage where such permission is required, thereby infringing certain exclusive rights granted to the copyright holder, such as the right to reproduce, distribute, display or perform the protected work, or to make derivative works

Theft is the taking of another person's property or services without that person's permission or consent with the intent to deprive the rightful owner of it.

The correct term is probably greed: not giving back to the author of music, movie, software you use. But greed is also the foundation of our economy, so copyright owners had to come up with a different word.

Copyrights have very little to do with paying content creators. From the very first copyright law (the Statute of Anne) it was about securing profits for the industry, who invariably give only a tiny slice of those profits, if anything, to the content creators. Hollywood studios are famous for trying to screw actors, screenwriters, and others out of their share of blockbuster movie profits. Likewise with the music industry -- most musicians do not make anything close to enough money on record sales (or the modern equivalent) to live on, even as the studios themselves bring in vast sums of money.

So in a sense you are right, "greed" is the operative word -- not on the part of people who download, but on the part of the people who benefit most from the copyright system.