This is classic passive-aggressive: push it harder, it’ll work better. Obviously, people know that pushing the printer harder won’t make it work better, we all know it deep in our hearts, but for some reason, our intuitive reaction when something doesn’t work properly is pushing harder, beating it or otherwise using force, partly to take out our frustration.
Although we’ve all heard countless times from our parents that using force is never the answer (even when it comes to printers which just won’t print), it’s our instinct to push the buttons harder. This person had enough of people abusing the printer, and he decided to try and put some sense into them – and what better way to do so than being passive-aggressive? You must admit, this is a pretty convincing note.