What is Basic 9 meant to teach you?

Correct me if I am wrong but what is basic 9 meant to teach people about null bytes?

A null byte is a string terminator, but in basic 9 it acts as a magical characters that by putting it on the end of a file name you want to search, it displays the source.

Would it not have been better to make the challenge about null bytes and directory transversal or removing mandatory file extensions?

I was not sure where to post this, so hopefully it is in the right place.