Even on Windows you can open the browser console and do
> console.log("hello")
Just for teaching basic prints, variables, loops and functions, terminal bash on macOS/Linux or Javascript console work just as well as Commodore 64 BASIC.
The problem is not that the environment is not available or setup is too difficult. The problem is that there's now way more competition from other shinies readily available (web, apps, games, videos). Even if you boot your home PC straight into a terminal, as soon as the kids find the way to a web browser it's game over. Even on 1980s home micros, if the kids got access to (pirated) games, practically none would volunterily keep on programming BASIC.
When you were 6 years old is a different time from now. You probably did not have an always-on connection. There was probably no such thing as Web 2.0. Computers were more difficult to use. Google did not exist. The Internet was perhaps still taking off...
When I was six years old, learning to program involved turning on the computer and typing
That’s what I want for my kids. And there’s nothing even remotely like it in today’s world.