One distinction for me between copying an online article and copying music or a game, is that with the latter, people are pirating it because they'd can't otherwise access it. They'd have to pay or inconvenience themselves somehow, so they go for the free version.

A piece of online content, assuming it's free, is something anyone can effortlessly access from anywhere.

So they may as well go to the original source, reward the author for his work, and not support someone else who's being more parasitic.