What this really points to is a new ecosystem which is now built on theft.

Only if you redefine "theft" to mean learning from copyrighted material, which is more expansive than anything the RIAA or other copyright cartels have ever argued.

it has destroyed the community of code

Speak for yourself. I'm in a Discord where a bunch of people are working with AIs and each other to get Linux running on Apple Silicon Macs, and it's great to see the rapid progress.

It may have no lines of code in common with Illustrator, but everything it has was taken from code that someone wrote.

I have shocking news about where the code that you write comes from.

If you reconstruct the book by taking random words clipped out of newspapers and pasted together

Sure, which is irrelevant because that's not what LLMs do. ("What about this study that found that you can get them to recite paragraphs from Harry Potter?" Well, I can recite large portions of the Ghostbusters screenplay and my brain is not illegal).

The question is, what's anyone's motivation to write anything anymore?

I wanted a thing, so I built it, and made it available in case other people want it too. AI doesn't affect this other than making it possible to build things faster.