Diminishes and eliminates are two different words for a reason. The other thing I think you're missing here is that there's a certain level of rationality implied with someone who robs a bank. Ignoring morals, sure, but rationality nonetheless.

Random shooting sprees tend to lack that rationality - as this one does. There's no chain of cause and effect that goes from "youtube demonetized my videos" to "I'm going to shoot random people at youtube with no understanding of their responsibility, and later myself".