Actually, they kinda are. Terrorism is about killing some people so you can influence the rest by fear. Genocide kills them all. If they’re all dead, how do you influence them with fear?

Am I missing something here?

edit: Do people think that any time someone blows up an innocent civilian, that’s an example of terrorism? If so, that’s a shitty definition. Terrorism is instilling terror into a population so you can push them into hurting themselves, usually because they’re too strong for you to defeat with more conventional military methods.