Your so-called advice is actually a opinion .
You don’t need to know the command line to be a good coder.
You need to know how to program, how to understand code logic ,how to code without tutorials to be a good programmer .
Sure , its good to know the command line the basics in extreme cases, But do what you are comfortable with.
And Windows also has a command line ,actually 2 on Win 10 — Command prompt & Power Shell .No reason to switch to the Linux/Mac OS terminal.