* What's your experience of BASIC, on what computers?
TI-83 BASIC was my entry into programming. I started with a quadratic equation program that let me do my homework more quickly/accurately than I could have done by hand, and ended a couple of years later with a tic-tac-toe program whose graph-based-drawing techniques were, in retrospect, pretty neat, but whose *airquotes* A.I. */airquotes* was a buggy gordian knot of GOTO statements that eventually made me throw up my hands and abandon the whole thing.
* What things prevent a child from making use of your current programming environment / languages you use?
That they're not seen as readily applicable to any real, current problem in their lives, and aren't available on devices that they already use regularly.
I fell into TI-83 BASIC because the TI was a thing that I was already using when doing my math homework... and learning to program helped me solve a very specific, real problem (quadratic equation homework sets), quickly… only after that quick win did I get curious about how this logical world inside the calculator worked, and what I could do with it. After bitten with that curiosity bug, the portability and always-in-the-backpack-availability of the machine kicked in -- suddenly I was programming every day on the way to school.
Hypothesis: you need to things to begin to learn anything new 1) a real problem to solve & 2) highly-available tools to solve it with.
I should note that a "problem" can take all kinds of forms -- I learned chess as a kid because my friend knew how to play, there was a fancy chess set in the living room of his house, and it was a way to fill the time & compete when I went over to hang out with him after school.