The origin of the term is not so evil:

https://en.wikipedia.org/wiki/Daemon_(computing)#Etymology

But we don't seem to care about origins of words, Master itself didn't mean slave owner until late in the 17th century.

And we'll stop in the event of the demonic invasion of Earth, but Doom 2 remains just a video game.

Demon, also spelled daemon, Classical Greek daimon, in Greek religion, a supernatural power. In Homer the term is used almost interchangeably with theos for a god. The distinction there is that theos emphasizes the personality of the god, and demon his activity.

Apparently copyright infringement is also tantamount to raping and pillaging on the high seas (piracy).