Its fanboy/girlism.
If you pirate content from their favorite author/artist/producer/whatever, basically all of their screeching comes down to a hysterical emotional response that you are hurting a person or group that they worship as God.
They just learn rhetoric to justify their emotions as a side effect, a consequence of wanting to be able to argue against the bad mean people that are hurting their favorite creatives.
They are naive, ignorant or misinformed, immature... usually believing in some kind 'just world' type worldview where everything is fair and square actually if you just follow the rules.
They don't understand that the actual 'losses' from piracy are far, far smaller than whatever the RIAA or game studios say it is.
They don't understand that the people who actually create or perform the art basically get paid a tiny fraction of what their labels or corporate overlords make.
They don't understand that some people are actually poor, and the poor deserve art as well.
They don't understand that when a reasonable cost forma product with reasonable ownership rights exist, a great, great many will prefer a streamlined but slightly costly method over a complex but monetarily costless method.
They don't understand that you don't really own anything which you can't use or view or listen to as you please without relying on some proprietary other system which may just poof that ability out of existence one day, without refunding you.