I wonder what else to call it. "Source code" is obvious and what everyone uses, but now I want something else to use.

Certainly true in many respects. However I don't think learning programming is much easier now than it was in the 80s.

Back then I had to bicycle to the library to borrow a book, and hope that the accompanying diskette with the compiler in it was still working.

Programming is still programming. Maybe becoming a professional software engineer is harder, though.

An abundance of choice can actually make things harder.

But overall it's so much easier these days. Even if you're spoiled for choice, you can get the tools and documentation for free. Back then it was either the BASIC interpreter that shipped with your computer (QBASIC for me) or the assembler (debug.com) or paying big bucks to buy a compiler. I was lucky that my dad could obtain a PASCAL and a C compiler through his work.

These days you might have too much choice but back then for a kid like me, the choice was what was available in the local library. So not much choice at all.

It was also what made demoscene competitions so interesting, there wasn't a web page explaining how to pull off those tricks.

It was curiosity and reading between the lines of those books that spiked out the curiosity to try out such tricks.