Yup, you go and explain that to, say. Ubiquiti. Their network management software still requires end-users to download JRE v8 (and noothing else: it won't work). And, once end-users do that, they get sued by Oracle. But, serves them right, right?
sudo apt-get install openjdk-8-jre-headless -y on ubuntu. Works fine with UniFi Controller. (what do you think they use on the cloud key?)