How did they end up thinking that everything must be done with terminal while using Ubuntu?
When asking for help in a Linux sub/forum/community, the answer will generally use the terminal because it works across desktops and even distros. It’s a lot easier to give one or two commands than it is to work out what distro, what desktop, and what settings the querier has, then describe the steps necessary in that particular GUI.
This may lead to the impression that the terminal is required for day to day use of Linux.