On many of the computers, like the C64, you actually had to type in commands to load files and games from disk and cassette. This was done directly in BASIC. So you were simply not able to ignore it. And most people didn't go further than 10 PRINT "HELLO", but when kids got together some would just show some skills and the other kids simply wanted to learn it as well.
Now, even if there are programming languages packaged on your computer, you still need to specifically use that program.