I am a developer by profession and I can tell you that I have tried to learn many of the programming languages out there.
Even if the syntax and all other concepts are different, the one thing that’s common for all these is that they all start with an example of printing out Hello World! on the screen .
I like to call this the Hello World! effect. Even though I have the complete liberty of printing anything on the screen for my first program, the simple line Hello World seems to give that perfect start. The moment you see that coming up as output on the new language you get that comfortable feeling of “Ok, I can tame this thing”. It’s gives a feeling that the language has started understanding you and is talking to you 😊.
I still don’t know who started this as a tradition. May be its the same way we say “Hello” over the phone. Someone started it and we are happy to follow it.